Odborné anglické texty pro oční optiky II.

Absolventská práce

Amira Behrami

Vyšší odborná škola zdravotnická a Střední zdravotnická škola Praha 1, Alšovo nábřeží 6

Studijní obor: Diplomovaný oční optik Vedoucí práce: Bc. Ondřej Bis

Datum odevzdání práce: 15. 4. 2014 Datum obhajoby:

Praha 2014

Prohlašuji, že jsem absolventskou práci vypracovala samostatně a všechny použité prameny jsem uvedla podle platného autorského zákona v seznamu použité literatury a zdrojů informací.

Praha 14. dubna 2014

Podpis:

Chtěla bych poděkovat Bc. Ondřeji Bisovi za odborné vedení, trpělivost a cenné rady, které mi pomohly tuto práci zpracovat.

Souhlasím s tím, aby moje absolventská práce byla půjčována ve Středisku vědeckých informací Vyšší odborné školy zdravotnické a Střední zdravotnické školy, Praha 1, Alšovo nábřeží 6.

Podpis:

ABSTRAKT

Amira Behrami Odborné anglické texty pro oční optiky II. Vyšší odborná škola zdravotnická a Střední zdravotnická škola, Praha 1, Alšovo nábřeží 6 Vedoucí práce: Bc. Ondřej Bis Absolventská práce, Praha: VOŠZ a SZŠ, 2014, 64 stran

Tato absolventská práce pojednává v anglickém jazyce o optických tématech, očních nemocech ale i o obecných tématech, se kterými se setkáváme běžně v každodenním životě. Podává přehled o očních nemocech (např. katarakta, glaukom, nevědomost nebo infekce a záněty očí), dále se také zaměřuje na obecná témata, se kterými by měl být seznámen každý oční optik (např. refrakční vady – astigmatismus a presbyopie, brýle, čočky – typy a materiály a kontaktní čočky) ale i s problematikou týkající se dnešní doby (např. computer vision syndrome, suché oko). Informace z těchto okruhů mohou pomoci očnímu optikovi obohatit jeho znalosti a také zlepšit schopnost komunikace v anglickém jazyce se zákazníkem v oční optice.

Klíčová slova: the eye, spectacles, lens, contact lenses, glasses, diseases

ABSTRAKT

Amira Behrami Odborné anglické texty pro oční optiky II. English texts for opticians II. Vyšší odborná škola zdravotnická a Střední zdravotnická škola, Praha 1, Alšovo nábřeží 6 Vedoucí práce: Bc. Ondřej Bis Absolventská práce, Praha: VOŠZ a SZŠ, 2014, 64 stran

This thesis is dealing in English language with basic topics from the field of the optics, eye diseases and also with general subjects which occur in our daily life. This work provides a survey of eyes diseases e.g. cataract, glaucoma, blindness or infections and inflammations of the eyes. It is focused on general topics which should be familiar to opticians e.g. refractive errors - astigmatism and presbyopia, glasses , lenses - types and materials, and contact lenses but also on problems related to daily life (such as computer vision syndrome, dry eye). Information from following areas can help the optician to enrich his/her knowledge and they can improve optician’s ability to communicate with the customer in English language.

Keywords: the eye, spectacles, lens, contact lenses, glasses, diseases

Obsah

Úvod ...... 9 1 Refractive errors: Astigmatism and Presbyopia ...... 10 1.1 Introduction ...... 10 1.1.1 Astigmatism ...... 11 1.1.1.1 Definition ...... 11 1.1.1.2 Classification ...... 11 1.1.1.3 Treatment ...... 11 1.1.2 Presbyopia ...... 12 1.1.2.1 Definition ...... 12 1.1.2.2 Symptoms ...... 13 1.1.2.3 Correction ...... 13 2 Eyestrain, Computer vision syndrome ...... 14 3 Cataract ...... 16 3.1 Introduction ...... 16 3.1.1 The cause of cataract ...... 16 3.1.2 Symptoms ...... 17 3.1.3 Treatment ...... 17 4 Glaucoma ...... 19 4.1 Definition ...... 19 4.2 The cause of glaucoma ...... 19 4.3 The risks of glaucoma ...... 20 4.4 Signs and symptoms ...... 20 4.5 Examination of patients with glaucoma or suspected glaucoma ...... 21 4.6 Treatment of glaucoma ...... 21 5 Lenses, types and materials ...... 22 5.1 Introduction ...... 22 5.1.1 Mineral lens ...... 22 5.1.2 Plastic or organic lens ...... 22 5.1.3 Photo chromatic ...... 23 5.1.4 Bifocal lens ...... 24 5.1.5 Multifocal lens ...... 25 6 Contact lenses ...... 26

6.1 Definition ...... 26 6.2 Types of contact lenses ...... 26 6.3 Special types ...... 27 6.4 Taking care of contact lenses ...... 29 7 Infections and inflammations of eyes ...... 30 7.1 Conjunctivitis ...... 30 7.2 Keratitis ...... 31 7.3 Iridocyclitis ...... 32 7.4 Stye ...... 32 7.5 Trachoma ...... 33 8 Blindness, diseases leading to blindness ...... 34 9 Dry eye, tears...... 37 10 Eye tests ...... 40 10.1 Visual acuity ...... 40 10.2 The autorefractor ...... 41 10.3 Pupillary reaction ...... 42 10.4 Tonometry ...... 42 10.5 Perimetery ...... 43 10.6 Cover tests ...... 43 10.7 Retinoscope ...... 44 11 Strabismus ...... 45 12 Glasses ...... 48 12.1 Types of frames ...... 48 12.2 Materials for glasses ...... 50 13 History of glasses ...... 52 Závěr ...... 56 Seznam použité literatury a zdrojů informací ...... 57

Úvod

Součástí učebních osnov studia na vyšší odborné škole zdravotnické je výuka cizího jazyka. V tomto předmětu se studenti zabývají odbornými tématy z daného oboru. V případě anglického jazyka v oboru oční optika se jedná o texty na témata zdravotnická (anatomie oka, nemoci oka, zdravý způsob života, refrakční vady, onemocnění oka, atd.) technická témata (např. materiály v oční optice, korekční pomůcky, vybavení oční optiky), technologická témata a také témata z historie tohoto oboru. S těmito tématy se oční optik může setkat přímo či nepřímo ve své praxi a také jako s teoretickými informacemi získanými z různých zdrojů. Proto je pro očního optika či optičku potřebné a vhodné umět se v těchto okruzích orientovat.

Schopnost komunikovat a dorozumět se v anglickém jazyce v těchto oblastech je v současné době pro oční optiky velmi žádoucí. Často se stává, že do oční optiky zavítá anglicky mluvící zákazník, který jistě ocení ochotu a schopnost očního optika dorozumět se s ním v anglickém jazyce. Ať se již jedná o vyřízení požadavku a zakázky zákazníka, o konzultaci na složitější téma nebo o přátelský rozhovor během návštěvy zákazníka, je velmi užitečné umět s ním v angličtině navázat kontakt a vyřídit jeho požadavky k jeho spokojenosti. Samozřejmě situace je jiná v očních optikách ve velkých městech, kde je pravděpodobnost situace, kdy se setkáme s anglicky mluvícím zákazníkem, daleko větší, než v městech menších. Nicméně s anglickým jazykem se může setkat každý oční optik, který například odebírá odborné časopisy a získává informace z oboru oční optika v rámci jeho dalšího vzdělávání z různých zdrojů, např. během školení v zahraničí. Proto je důležité mít znalosti odborných anglických výrazů a v dané problematice v anglickém jazyce se umět zorientovat.

Cílem této práce je zmapovat vybraná praktická a teoretická témata související s oborem oční optika a předložit soubor anglických textů pro oční optiky. Po gramatické stránce se bude jednat o angličtinu středoškolskou s výskytem řady odborných výrazů. Témata, u kterých to bude vhodné a užitečné, bude vložen obrázek s popisem.

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1 Refractive errors: Astigmatism and Presbyopia

1.1 Introduction

“Refractive error is a failure of the eye to focus light from an object on to the retina to form a clear image. It is a frequent cause of reduced visual function. If there is a refractive error when viewing a distant object the eye is described as ametropic. Ametropia can be divided into myopia („short-sightedness“), hypermetropia (hyperopia-„long-sightedness“) and astigmatism. If there is no refractive error when viewing a distant object the eyes is said to be emmetropic.” (1)

Figure 1 Normal eye and Astigmatic eye Table 1 Summary of definitons

Term Definition Optical correction Emmetropia No refractive error when Nil looking at a distant objects Myopia Light from distant object Concave lens focuses in front of the retina Hypermetropia Light from distant object Convex lens focuses beyond the retina Astigmatism Optical power of eye uneven Toric lens across different meridians Presbyopia Loss of normal Convex lens accommodation with failure to focus on near objects

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1.1.1 Astigmatism

1.1.1.1 Definition

“Astigmatism is where the refracting power of the eye is different in different meridians. It is defined in terms of its magnitude and direction. In the adult population up to 20% have astigmatism > 1D.” (1)

Astigmatism is a condition when the eye is not the same at all levels of optical power. The observed point is reflected into a complex shape with two perpendicular lines of focal maxim. The most common cause is a congenital irregular curvature of the cornea, traumatic and postoperative conditions. (3)

1.1.1.2 Classification

“Astigmatism may be regular (principal meridians 90° apart and so correctable by a toric lens) or irregular. Regular astigmatism may be „with-the-rule“ when the steepest meridian is at 90°, „against-the-rule“ when it is at 180°, or oblique where the principal meridians lie more than 20°from both 90°and 180°. Irregular astigmatism usually arises from an uneven corneal surface (e.g. scarring, keratoconus).” (1) Low degree of astigmatism (about + 0.25 D) is found with almost all individuals. Approximately 15% of the population have astigmatism stronger than 1 cylinder values.

1.1.1.3 Treatment

“Correction of astigmatism is treated with spectacles using toric lenses (i.e. with different power in different meridians), CLs (contact lenses) or refractive surgery” (1) Cylindrical glasses are prescribed which refract the rays in one plane. Cylindrical glass has a diopter values and an axis which is perpendicular to the plane of force. The combination of cylindrical and spherical glass forms glass toric. Correction of astigmatism with glasses is associated with induction of meridional anizeikonie (different magnification image in different planes), which sometimes reduces tolerance correction. The difficulties are more frequent and more serious at astigmatism in oblique axes. With adults, we start with a full correction and test individual tolerability. To children, we always prescribe full correction,

11 which is more easily tolerated by them. Irregular astigmatism (e.g. astigmatism without axial symmetry) cannot be corrected by glasses. Good effect can be achieved with hard contact lenses. (3)

“CLs are particularly suited to the correction of astigmatism as their rigidity allows the space between the lens and cornea to become filled by the tear film to form the „lacrimal lens“. This effectively neutralizes corneal astigmatism. In contrast hydrogel CLs are less rigid and adopt the same shape as the cornea. Therefore, if a hydrogel CL is to be used to treat astigmatism, a toric design will be necessary. A certain degree of astigmatism may also be corrected as part of refractive surgery procedures.”(1)

1.1.2 Presbyopia

1.1.2.1 Definition

Presbyopia is a loss of normal vision accommodation with failure to focus on near objects. Accommodative stimulus leads to contraction of the circular part of the ciliary muscle. Own lens reduces the flexibility of its equatorial diameter. Redistribution of the content of the lens increases the curvature of the front and rear walls and thus the optical power of the entire lens. (3)

Figure 2 Presbyopic eye Presbyopia is a physiological condition of inability to focus at normal reading distance. It usually appears with people after 40 years of age. The cause of the sclerotic lens is changing. The lens is unable to take a curved shape. The intraocular lens starts losing its elasticity. At first it is very difficult to focus on near objects. Later it is also difficult to focus on distant 12 objects. Symptoms of presbyopia include the increase in reading distance, decrease of visual acuity because of bad lighting, inability to focus on short distances, the worsening problems in the course of the day. (4)

1.1.2.2 Symptoms

One of the symptoms of presbyopia is increasing reading distance. Presbyopic people put off the text in an effort to get closer to the point where it may not involve full accommodation. The vision is blurred when person switch looking from the distance and to close objects. Early presbyopia is accompanied by ciliary spasms that distort distance vision. Symptoms can get worse during the day. Patient may also have other symptoms for example: headaches, double vision, blurred vision at normal reading distance etc. (3)

1.1.2.3 Correction

“The correction for difficulty in reading is usually a convex lens or a weaker concave one used for close work. The emmetrope will find that his reading correction actually blurs his distance sight. Hence the need to wear spectacles for close work only, or alternatively half spectacles, which allow clear unaided distance vision over the top of the correction. The correction for the myopia is achieved either by using a weaker concave lens, or indeed using no lens at all. Thus, some myopic person of presbyopic age simply take off their distance spectacles in order to read. For hypermetropic person developing presbyopia, a stronger convex lens is needed for near than for distance vision.” (2)

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2 Eyestrain, Computer vision syndrome

Long term staring at a computer screen, tablet or mobile phone has become an absolute standard of the modern era. However, this standard harms the human visual system. Increased demands on the eye causes so-called computer vision syndrome. It is a problem which comes from a combination of unnatural tension of the eye muscles and specific body posture while working on computer. Up to 90% of people working with computer experience some of the symptoms of CVS. These problems don’t concern only adults, who spend their working hours in front of computer monitors but more often it concerns children who use a computer for entertainment or study. (12)

A monitor is creating a very demanding environment for our eyes, because it doesn’t provide a sharp image as it appears to us and our eyes must constantly focus. There is no proof that computer vision syndrome could cause serious or permanent damage to our eyes, such as cataracts. On the other hand, working with a computer can often cause various problems such as blurred vision, double vision, dry eyes, red eyes or headaches or neck pain and back pain. Although it is nothing serious, eye problems can be very uncomfortable for our work and also significantly reduce the working efficiency. (11)

CVS symptoms can develop with a significant contribution of the uncorrected eye defects, especially hypermetropia, astigmatism and presbyopia. Another factor for the CVS is lack of moistening of the cornea. When a person is looking into the distance with relaxed look our eyelids blink in average 22 times per a minute. On the other hand when we are reading a book, a focused person blinks ten times. When we just stare at the display person blinks just eight times in a minute. (12)

The tear film, which is spread over the surface by blinking of the eye, forms on its surface a thin continuous layer which protects the eye. If the tear film is weak or disturbed, eyes react with congestion (an excessive or abnormal accumulation of blood or other fluid in a body part or blood vessel - http://dictionary.reference.com/browse/congestion) of the blood vessels, causing discomfort. Many of the symptoms of CVS are only temporary and will disappear after working with a computer. (12)

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However, many individuals experience vision problems such as blurred distance vision, even after completion of computer work. It is a good idea to get your eyes regularly examined, even if you feel that you can see well. Seeing well might be only a subjective feeling. (13)

In order to prevent tired and overworked eyes there are some important points such as appropriate light conditions, brightness and contrast of your monitor. Do not let yourself to be dazzled – modifying your monitor display setting can help to reduce eye strain and fatigue. Adjust your monitor height for maximum eye comfort e.g. place the center of the screen from 55 to 65 centimeters below your horizontal line of sight. In this position, you will not have to stretch your neck or strain your eyes. Give your eyes a regularly break from your work. Take a 20 seconds break and look at something else for example from the window or just look around the room. While working on the computer, it is important not to forget to blink. Blinking keeps the front part of the eye moist. Relief and moisturizing of the eye can be achieved by a yawn. (13)

Glasses and contact lenses prescribed for general use may not be in many cases ideal for computer work. If a computer user does not need glasses for distance or near vision, they may consider range of special lenses that are intended to work with a computer. With a use of contact lenses, some people choose to correct one eye for near and one eye for far vision. This is called “monovision” and it eliminates the need for bifocals or reading glasses, but it can affect depth perception. Sometimes monovision can be produced through laser vision correction. There are also bifocal contact lenses that can correct both near and far vision in both eyes (11).

Figure 3 Proper posture in front of the computer

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3 Cataract

3.1 Introduction

“Cataract is a disturbance of the transparency of the lens of the eye. The lens acts as part of the focusing mechanism and is situated symmetrically across and in a plane perpendicular to the optical axis of the eye. It is held in this position by the zonule, or suspensory ligament, a curious sheet of fibrillar tissue which stretches from the ciliary body to the equatorial region of the lens. The shape of the lens is altered in accommodation. In this function the ciliary muscle contracts, narrowing the ring attachment of the zonule. The tension of this on the lens relaxes, and the lens then bulgus on account of the intrinsic elasticity of its capsule.” (2)

In this position passage of light rays inside the eye is disturbed. The disease is developing slowly but symptoms are getting worse. Typical is a slow progressive decline in visual acuity for months and years. Cataract is not associated with pain and redness of the eye. Advanced cataract is visible by a simple look. Most people older than 70 years have cataract at certain degree least at one eye. The lens may become cloudy even at younger patients. At the age of 65 years there is a certain degree of clouding of the lens and it is proven in up to 50% of the population over 75 years old cataract affects even 70% of the population. As you age, proteins in your lens begin to break down and the lens becomes cloudy. (7)

Figure 4 Cataract

3.1.1 The cause of cataract

Congenital cataract is either hereditary or is produced during the life as viral inflammations or disorders of development. Cataract can affect one eye or both eyes. Although it is not common, some babies are born with cataracts or develop them within the first year of life. We 16 have various types of cataracts. Senile cataract occurs after the 50 year of age and we cannot identify other cause. Presenile cataracts are caused with no obvious cause and it appears before the 50 year of age. Traumatic cataract occurs at perforating eye injury, after eye contusion, the influence of radiation or by electric discharge. It also can follow bruin or penetrating injury; diabetic cataract may be a complication of severe untreated diabetes. Complicated cataract is cataract which occurs as a complication of eye diseases or undesirable effect of its treatment. Toxic cataract arises in connection with certain industrial poisons. (6)

3.1.2 Symptoms

Symptoms of cataracts may be a decrease in visual acuity, visual disturbances on a clear day, vision that is cloudy, blurry, foggy, ionizing radiation (X-rays), problems with glare during the day, chronic eye disease, diabetes mellitus and age. (6)

Figure 5 Normal eye with difference of clear and cloudy lens

3.1.3 Treatment

The treatment is to remove the opaque lens surgically and compensate for the loss of focusing power by prescribing spectacles with a suitable convex lens to restore eyesight. “Usually one eye is operated on at a time. In most people the operation is done under local anesthetic. This means that you are awake during the operation but it is not painful because local anesthetic eye drops are used to numb your eye. The operation is performed, using a microscope, through a very small opening in the eye. When the eye is numb, the surgeon makes a tiny hole in the front of the eye at the edge of the cornea. Then, the surgeon pushes a tiny thin

17 instrument into the lens through the front part of the lens capsule. The instrument emits ultrasound waves that break up the contents of the lens within the lens capsule. The contents of the lens are then removed by suction. Once the lens material is removed, a clear plastic lens is placed within the lens capsule through the hole made in the front part of the lens capsule. Usually no stitches are needed. You may have to wear a pad over your eye after the operation. In the vast majority of cases, the operation is successful and vision improves immediately. In a small number of cases, complications occur. For example, bleeding into the eye, infection, inflammation of the eye and damage to the cornea or to other parts of the eye. These are all uncommon, can often be treated, but are very occasionally serious enough to cause permanent visual problems.” (15)

Figure 6 Removing cataract from lens

Figure 7 Implant of intraocular lens

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4 Glaucoma

4.1 Definition

Glaucoma is a disease in which the optic nerve is damaged. The optic nerve leads all the information about images that our eyes see. This disease leads to partial or complete loss of vision. Glaucoma is the term used to describe many conditions in which high eye pressure produces undesirable effects on the eye and sight. Glaucoma is not a single disease. When a patient is diagnosed as having glaucoma, it usually means that he has one of two particular conditions, the primary glaucoma. (13)

Figure 8 Developing of glaucoma

4.2 The cause of glaucoma

The main causes of glaucoma and optic nerve degeneration is increased intraocular pressure. It is a condition in which the pressure of fluid inside the eye is increased; it may be caused by gradual blockage of the narrow canal through which excess fluid inside the eye drains away. After some time the optic nerve may completely die out. There are typically no early warning signs or painful symptoms. This condition often starts slowly, so that the person affected may not seek medical advice until a late stage, when the damage has been done. Increased intraocular pressure does not cause any pain or other discomfort. (3)

The procedure of vision loss in glaucoma is characterized by a small interruption in the visual field, which a person may not even notice. As the disease progresses, the interruptions in the visual field become hard to overlook. Person loses the so-called peripheral vision and they see only shadows and red spots. If the optic nerve dies completely, there is a complete loss of

19 vision. Glaucoma can be treated, but a patient must come in time. Any degenerative changes in the optic nerve are irreversible. (4)

4.3 The risks of glaucoma

The most important risk factor for glaucoma is increased intraocular pressure. Although the disease is usually associated with an increase in the fluid pressure inside the eye, other theories include lack of adequate blood supply to the nerve. If too much fluid is produced or the fluid cannot escape, then the pressure in the eye rises Even if patient doesn't know that he has a high eye pressure, the high pressure can cause a harmful and irreversible changes in the optic nerve. When the eye has been damaged and the patient has interruptions in the visual field, the repair is too late. It is therefore recommended to undergo regular examinations by the ophthalmologist. Recommended frequency of this examination is once in two years to 45 years of age and once in a year after 45 year of age. Glaucoma is much more common among older people. You are six times more likely to get glaucoma if you are over 45 years old. The most common type of glaucoma, primary open-angle glaucoma, is hereditary. If one of your relatives has glaucoma, the risk is higher. Vision harms particularly strongly nearsighted people who have an increased risk of glaucoma. To some extent this is also true of long sighted people. Glaucoma is often developed in people who have significantly low blood pressure. Injury to the eye may cause secondary open-angle glaucoma. This type of glaucoma can occur immediately after the injury or years later. (13)

4.4 Signs and symptoms

The most common form of glaucoma is chronic and it begins slowly and very quietly, so that the sick person does not experience any difficulties and has no reason to consult an ophthalmologist. Most people who have glaucoma feel fine and do not notice a change in their vision, because the initial loss of vision is of side or peripheral vision, and the visual acuity or sharpness of vision is maintained until late in the disease. To avoid this, it is recommended to regularly visit the eye doctor for examination. By the time a patient is aware of vision loss, the disease is usually quite advanced. Eye doctor is able to catch with special instruments a beginning of glaucoma. (13)

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4.5 Examination of patients with glaucoma or suspected glaucoma

Slit-lamp examination may help in the assessment of depth of the anterior chamber and the findings of the anterior segment. Gonioscopy is an important diagnostic method for classification of glaucoma. We find that the angle is open or closed. Ophthalmoscopy is the investigation of eye ground, which can reveal even beginning glaucomatous changes. Eye drops are used to dilate the pupil so that the doctor can see through your eye to examine the shape and color of the optic nerve. Tonometry is the one of the basic investigative techniques. Tonometry measures the pressure within your eye. During tonometry, eye drops are used to numb the eye. Perimetry is a visual field test that produces a map of your complete field of vision. The visual field is the area that the eye sees a fixing point. During this test, you will be asked to look straight ahead and then indicate when a moving light passes your peripheral (or side) vision. (4)

4.6 Treatment of glaucoma

Glaucoma cannot be cured. The focus and goal of treatment is to control the disease and prevent or slow any further visual damage from occurring. It is essential difference in the therapeutic approach to glaucoma with open and closed-angle glaucoma. The main treatment methods are of pharmacotherapy, laser trabeculoplasty and filtration surgery. With open angle glaucoma the primary care is pharmacotherapy, while with the closed angle glaucoma is the reduction of intraocular pressure with surgical treatment. With pharmacotherapy should be used a one preparation or a maximum combination of two drugs. The purpose of pharmacotherapy and surgical treatment is to reduce the pressure in the affected eye, so called intraocular pressure. (3)

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5 Lenses, types and materials

5.1 Introduction

“Lenses may be made from glasses, or various plastics (CR-39 or polycarbonate). Glass has the advantage of excellent optical properties, scratch resistance and has been used in spectacles. The commonest glasses are ophthalmic Crown glass (refractive index 1, 52) but alternative higher refractive index glasses are also available, e.g. flint glasses (refractive index 1, 62) may be used with crown glass infused bifocals.” (1)

5.1.1 Mineral lens

First mineral lenses are marked as Crown glass. The name comes from the English "crown glass" which was derived from the appearance of circular glass plates which were similar to shape of a crown. Crown glass is also known as B 270. B 270 has both good and bad properties. His advantage is dimensional stability. It has high visibility and it is optically very pure. It has a high hardness surface and resistance to weather condition, acids and alkalis. On his surface we can apply different layers. Crown glass has poor thermal conductivity at the transition from a cold environment to a warm environment - it fogs easily. It is easy to break it and it is not suitable for children and athletes. The name “Flint glass“ is derived from previously used pure and bright flint which was exploited near the city Flint. Glass is very hard and has a lot of plumbic oxide (PbO). Although the lenses have a high dispersion and reflectance, the thickness is significantly smaller, which is suitable for high myopic correction. We should apply an anti-reflective coating on lenses. (4)

5.1.2 Plastic or organic lens

“Plastics have the advantage of a higher refractive index and lower density than glass permitting thinner, lighter lenses. They are also safer if shattered. CR-39 is the preferred plastic for most applications as it has excellent optical properties, is more scratch resistance, and has low transmission of harmful UV light. Polycarbonate is mainly used for safety goggles as it is the most resistant to impact; its main disadvantage is reduced optical quality due to high light dispersion.” (1)

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Organic or plastic lenses compared to mineral lenses have low weight. Lenses do not break easily and they are suitable for children and for sport. The transition from cold to warm environment is better because there is not much fog on lens. The surface is softer therefore they can be easily scratched. Under the high temperature they can change their shape. The first transparent plastic was PMMA. CR39 is the oldest plastic material and it was used for the manufacture of spectacle lenses. A material that is first tried around in 1955 was polycarbonate. Polycarbonate is flexible and lightweight and it is ideal for sport glasses and protective sun lenses. Trivex was introduced in 2001. It is light and can be produced very thin. He has very good optical properties. It is very suitable for drilled glasses. (28)

Figure 9 CR 39

5.1.3 Photo chromatic

“Photo chromatic lenses have a special chemical coating that makes them change to a dark tint in the sunlight and turn clear indoors. Photo chromatic lenses are great for people who do not wish to carry a separate pair of prescription sunglasses. It is important to recognize that these lenses do not darken as well while driving a car. The windshield prevents most of the UV light from reaching the lens.” (16) “Most photochromic won’t darken behind the windshield since the windshield itself blocks out the UV light required to make the lens change color. Transitions came up with a unique product that solves this problem in the form of Drivewear. Drivewear lenses will remain dark behind the windshield making them the ultimate option in driving lens material.” (17)

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Figure 10 Photo chromatic lens According to type of the lens, they are classified as a single vision, bifocal and multifocal. Single vision lenses are lenses with one focal point. They correct the defect always for one distance. They can solve the problem of distance vision and intermediate distance for example the computers. These lenses have a plus or minus value or they can correct the astigmatism. (28)

5.1.4 Bifocal lens

Bifocal lens allows you to see both near and distant, they correct presbyopia. This lens corrects presbyopia. Basic lens was made for distance vision but with bifocal lens there is a melted or refined piece for near vision. The advantage is that patient can use one pair of spectacles for both vision. The problem may occur if he wants to look somewhere between these two distances, i.e. in the middle distance.(28)

Figure 11 Bifocal lens

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5.1.5 Multifocal lens

Modern multifocal lens provides a comfortable view at all distances. Lenses are divided into three areas of vision. Patient looks through the area for correction to distance. Near vision is provided from the lower part of the lens, which includes a prescribed correction. Between these areas is so called a progressive zone and this is a field where the diopter value is changed and everyone can easily concentrate to find their diopter values and they can also find a vision from medium distance. These lenses are very esthetic, comfortable and convenient. (28)

Figure 12 Mulifocal lens

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6 Contact lenses

6.1 Definition

Contact lenses are optical correction devices worn directly on the cornea of the eye. The curvature of the anterior surface of the cornea is replaced with the curvature of the front surface of contact lenses. They may be used for correction of refractive error or for a wide range of therapeutic applications, or for cosmetic. According to the materials we can divide contact lenses on hard, soft and permeable for gases. For many, contact lenses provide flexibility and convenience. Contact lenses can be used to correct a variety of refractive errors such as Myopia (nearsightedness), Hyperopia (farsightedness), Astigmatism, and Presbyopia (poor focusing with reading material and other near vision tasks). (4)

Figure 13 Contact lens

6.2 Types of contact lenses

Hard contact lenses are made from polymethylmethacrylate. Hard and perfectly clear material provides excellent optical quality and durability. Hard contact lenses correct regular and irregular astigmatism and they are easy to maintain. Application of hard CL's is harder than with soft lenses. (4)

Soft contact lenses are made of hydroxyethylmethacrylate or related polymers. The softness of the material and high water content provides good compatibility and rapid adaptation. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses. (4)

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Daily wear mode is used for the hard and soft lenses. For the safety of your eyes, it is recommended that contacts should be removed at bedtime due to risk of infection and risk of contact lens intolerance. (4)

Duration of tolerance and daily life is determined by the type of lenses, correctness of applications, individual tolerance and the quality of the environment. Part of the daily routine of wearing their lenses are daily cleaning and sterilization. (4)

6.3 Special types

There are also special types of contact lenses. Appropriately chosen hard contact lens is able to eliminate corneal astigmatism. Hard contact lens that is appropriately chosen is able to eliminate corneal astigmatism. Toric contact lenses are designed to correct astigmatism. Toric contact lenses correct for astigmatism issues that arise from a different curvature of the cornea or lens in your eye. Toric lenses have two powers in them, created with curvatures at different angles - diopter spherical and cylindrical diopters (cylinder). (29)

Some toric lenses are heavier at the bottom to keep from rotating. They work best when the astigmatism in the 90 ° and 180 °. The application is never easy and often ends with a failure. (29)

Bifocal contact lenses are designed to provide good vision to people who have a condition called presbyopia. Bifocal contact lenses are based on two possible principles. One of the possibilities is to wear reading glasses and use contact lenses for distant vision. The second option is to use one eye for distance vision and one for near vision so called "monovision". The newest ways to correct presbyopia by contact lenses is contact lenses with both distances (near and far). Bifocal contact lenses have been around for many years, but until recently they weren't very popular. A large percent of people stop wear the bifocal contact lens. (31)

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Figure 14 Bifocal contact lens “Other types of special types of contact lenses are therapeutic contact lenses, which we can use after operation like a medication support. Commonly called "bandage" contact lenses, their range of applications is much wider than this implies. For example: promotion of epithelial wound healing, protection of ocular surface, pain relief and many other.” (1)

“In addition to their important "therapeutic" role in improving cosmetics for a number of pathological conditions, cosmetic contact lens are widely available for changing eye color and for "novelty" or theatrical use(e.g. cat-eyes, nation flags. etc.)” (1)

Contact lenses are replacement of glasses for cosmetic or professional reasons. From an optical point of view is advantage unobstructed field of vision. Another significant advantage is that contact lenses do not fog in humid conditions. The disadvantages of using of contact lenses are their price, easy of damage and the required adaptations. The biggest disadvantage is the risk of infectious and non-infectious complications. (32)

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6.4 Taking care of contact lenses

In the morning

Figure 15 Taking care of contact lenses at the morning Wash your hands with soap and dry them with a towel. Remove contact lenses from the case. Place the lens on the palm of the hand then wash it with a fresh solution. Insert the lens into the eye. Pour a solution of the lens case, rinse out the case with a fresh solution and shake dry. Let the lens case open to dry. (13)

In the evening

Figure 16 Taking care of contact lenses at the evening Wash your hands with soap and dry them with a towel. Fill a clean lens case just below of the edge with a solution. Remove the lens from the eye and put it in the palm of your hand. Drop on a few drops of the solution and gently rub on each side for 10 seconds. Carefully wash off each side of the lens for 5 seconds with a fresh solution. Insert a clear lens into the case filled with a fresh solution and leave it there until the further use. (13)

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7 Infections and inflammations of eyes

“The eye is a delicate and sensitive organ and if its structure or integrity is affected, e.g. when the front of the eye is scratched, an infection can occur. In addition, the eye and its surrounding tissues are prone to a wide range of non-infectious inflammatory disorders. When either the outside or inside of the eye becomes infected or inflamed, immediate treatment is necessary to avoid irreparable damage which in severe cases can permanently affect the sight.” (18) Inflammations can affect almost every part of eyes and their surrounding area. We can divide inflammations of the eyes on the anterior and posterior segment of the eye and intraocular inflammation and inflammation around the eye.

7.1 Conjunctivitis

Conjunctivitis is the most common eye diseases. Conjunctivitis is inflammation of the conjuctictiva, the transparent covering on the inside of the eyelids and the surface of the eye up to the cornea. The condition may be acute or chronic. The causes for conjunctivitis may be infectious, non-infectious or allergic. Inflammations are usually caused by bacteria, viruses or parasites. We can get inflammation from touching our eyes with dirty fingers or from pool water during swimming or for example from a shared towel. (35)

Figure 17 Bacterial conjuctivitis The main symptoms of conjunctivitis are a strong redness of the eye, pain or itching of the eye. There may be a watery discharge in the eyes. Patient can feel a foreign body sensation in the eye that is often associated with discharge. Also the eyelids are very swollen. This is a condition that affects both eyes. In some cases, it may be affected only one eye, e.g. chlamydial or viral conjunctivitis. (35)

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“Help and treatment of eye inflammations depends on what area of the eye is inflamed, the severity and the cause of the condition. While some eye inflammations, such as those caused by allergies, are generally not serious.”(19) Each eye is treated separately. If the inflammation is not relieved in a few days, it is good to consult an ophthalmologist. We are using an antibiotic therapy for bacterial and chlamydial conjunctivitis. Antibiotic are served locally in the form of eye drops or ointments. Antibiotic are most often served in the form of pills. The viral conjunctivitis cannot be treated by antibiotics. It is recommended to treat viral conjunctivitis by cold compress therapy, medication, or antivirals in the drops or ointment. (34)

7.2 Keratitis

“Superficial keratitis, an inflammation involving the surface of cornea, is the most common type of inflammation affecting the cornea. Deep keratitis occasionally arises as a primary condition, but is usually a consequence of the superficial type.”(2) Inflammation of the cornea is more dangerous than conjunctivitis. They can cause a reduction of visual acuity and even loss of eyesight in the worst case. The causes of inflammation of the cornea are usually bacterial but more often viral infections. “Noninfectious keratitis can be caused by a relatively minor injury, wearing your contact lenses too long. Infectious keratitis can be caused by bacteria, viruses, fungi and parasites.” (20)

Figure 18 Keratitis The symptoms are eye pain, foreign body sensation in the eye, watery eye, irritability, loss of corneal shine, red eyes, swollen eyes, sensitivity to light and vision disorders. There is some possible blurring of vision, depending on the situation of the ulcer. In this case we need to visit an eye doctor. Irritation may be relieved by washing the eyes with warm, salty water or

31 by applying a cold compresses. Your doctor will recommend to bandage both eyes which prevents their movement and this can speed healing process. (33)

Inflammation of the cornea is treated by eye drops. Eye drops are prescribed for different inflammation of the cornea (bacterial, viral and others). If this treatment doesn't respond to medication it may be necessary to provide a surgical procedure. By this procedure we need to remove a dead tissue of the cornea. The doctor may also recommend to transplant the cornea. It is good not to expose eyes to bright light during the treatment. We need to wear dark glasses, minimize working with a computer and watching TV. (34)

7.3 Iridocyclitis

“Iridocyclitis is caused by bacterial, viral or fungal infection and also can be caused by perforating eye injury or by blood contamination. Another cause may be related to a general disease such as rheumatoid arthritis. 1Inflammation of the iris and ciliary body usually presents as an acute and possibly painful, often photophobic, red eye with blurred vision and injection characteristically around the corneoscleral junction.” (2) These conditions can be treated with eye drops. (35)

Figure 19 Iridocyclitis

7.4 Stye

If the root of an eyelash becomes infected, a painful swelling known as a stye occurs. It is the most common inflammation around the eye. On the upper or lower eyelid appears a painful red lump. Lump arises as a result of blockage of the surface glands on the eyelid. Blockage of 32 an oil-producing gland on the eyelid causes a small, hard, painless lump called a chalazion or meibomium cyst, which should be treated by a doctor. There are typical symptoms of stye - redness, swelling, and pain. A stye should be bathed with warm salt water to encourage it to discharge and to clean away the pus. It can also be applying a warm compression. A stye usually bursts and disappears by itself but, if the complications still remain, it is good to visit an eye doctor. (34)

Figure 20 Stye

7.5 Trachoma

“Trachoma is an infective conjunctivitis, which is endemic in many underdeveloped countries and probably remains the commonest cause of blindness worldwide. It typically starts as follicular conjunctivitis, often acute, of the upper tarsal conjunctiva, later involving the conjunctiva of the eyeball, the cornea and the lid substance.” (2) If the trachoma is not treated in the early stages, it causes scarring of the cornea. The eyelids swell and produce a discharge, and the sufferer cannot tolerate bright light. Trachoma can be successfully treated with antibiotics. In countries like Africa and South America where general hygiene is poor trachoma is not treated right.

Figure 21 Trachom

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8 Blindness, diseases leading to blindness

According to the World Health Organization, the number of blind people in the world is around 45 million and about 314 million people worldwide are visually impaired. The highest occurrence of blindness is in some area of Africa and the lowest occurrence of blindness is in Europe, Australia and North America. At this time visually handicapped people and blind people represent the most serious global problems. (8)

During the examination it is important to write down a vizus in the better eye with best possible correction. Visually impaired are classified as partially sighted - with vision worse than 6/18 on the better eye after correction and practically blind patients with vision less than 3/60 or a visual field of 10 degrees or less. The rest have some vision, from light perception alone to relatively good acuity. (8)

The main causes of visual impairment and blindness are different in each country and are closely related to the economic, social, environmental and cultural factors. In developing countries are visual impairment and blindness associated mainly with infections, malnutrition, inoperable cataracts and injuries, and it affects all age groups. (5)

The most common cause of blindness in developing countries are following diseases: Trachoma is the most common disease in the world. It occurs mainly in Northern and Central Africa, Southeast Asia and South America. The disease is highly infectious. Onchocerciasis (river blindness) is the second most common cause of blindness in the world after trachoma. The disease occurs most often near rivers (Central Africa, Central America). Xerophthalmia (dry eye) is the third most common cause of blindness. It occurs in Southeast Asia in some areas of Africa and South America. The disease is caused by a lack of vitamin A and it affects children under age of 6. There are causes of blindness occurring in both developing and developed countries. (5)

Cataract is a common cause of blindness in the world. Approximately 17 million people have cataract and every year more and more people are affected. There is no prevention of cataracts. Blindness as a result of cataract can be removed by surgery. At present, doctor removes only 10-20% of cataracts. (8)

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Glaucoma participates on overall blindness across the globe. Prevention of glaucoma is related to the early detection of residual intraocular pressure. Macular degeneration is a common cause of central vision in people over 65 years old. The one of the most common causes of blindness in developed countries is diabetic retinopathy, which is rising as a complication of diabetes mellitus. (6)

For visually impaired there are a social care and special education of all age categories. Children with blindness may attend a pre-school and boarding primary school with special education and they can learn how to live with their handicap. Then there are secondary schools as well as grammar school and business academy for visually impaired youth. (5)

In individual cases, a blind person can study at the regular high schools and colleges. For adult population there is a rehabilitation center which is fully established by everything that a person with a lack of vision needs. The role of the center is to prepare adults for the life without sight. The center teaches orientation and mobility, rehearsing activities for independent living, reading and writing Braille, etc. To read braille, a person feels a series of little bumps that are associated with letters in the alphabet. (8)

Figure 22 Braille There are many means that can help them to get ease with their lives. “Many individuals who are blind or visually impaired use a long white cane with red tip as a mobility device. In the most common technique, the cane is extended and swung back and forth across their body in rhythm with their steps to provide information about the environment directly in front of them, such as elevation changes or obstacles. Dog guides are carefully trained service animals used as travel tools by approximately 2% of people who are blind. The dog responds to the

35 commands of its handler, such as right, left and forward. The dog guides the handler around obstacles and stops at curbs or stairs.” (21) There are another tools which can help blind person with his life needs such as blood glucose meter and thermometer with voice or Braille thermometer.

Figure 23 A folded white cane

Figure 24 Guide dog

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9 Dry eye, tears

The eye is our most important sense, that’s why we have to take care of them properly. Tears are the most natural protector of the eyes. Every movement of the eye lids apply a thin layer of the tear film that keeps the surface of the eye smooth, clean and moist and protects eye from harmful substances. A condition, when the sensitive system of production and distribution of tears is disturbed, is known as "dry eye". These days it affects one adult of five.(36)

Dry eye is a result of the loss or reduction in the ability of eye to create normal tears. Dry eyes may occur when the system doesn’t produce enough tears or produce poor-quality tears. The whole range of factors may have caused the problem or contribute to its creation. Some of the problems are related to age or environment. “Environmental factors can also play a role in eyes drying up. Examples include dusty air, dry or windy weather, or fumes like cigarette smoke which can evaporate tears much speedily or hamper their effectiveness. This is especially a cause for dry eyes in contact lens wearers as the lenses absorb lubrication and the tear film.”(22) It is a common and treatable disease. Women are affected more often than men especially in menopause. (36)

Figure 25 The lacrimal drainage system The cause of dry eye can also be a quality of tears. Normal tears have three layers - water-the main middle watery layer, oil-the thin outer oily (lipid) layer and mucus - the thin inner mucus layer. “The outer lipid section consists of an oily film that counters evaporation and keeps the eye moistened. The middle region is made of mostly water that moisturizes the eyes

37 and some nutrients and proteins that assist in limiting eye infections. The inner coating contains mucous that allows the tear film to spread and reduces evaporation from the eye. Each layer is vital to the health of the eyes and different parts of the eye add to the tears which can lead to any number of possible problems like shortage of nutrients or mucous. It also shows that dry eyes are more likely if there is a depletion of tears due to reduction of generation because of age or by weather issues like windy days which can dry out tears quickly.” (22)

Tear production can be reduced with certain medications, such as antihistamines, birth control pills, diuretics, heart medicines and blood vessels, painkillers and anti-inflammatory, and also some diseases, such as diabetes or rheumatoid arthritis. Eye doctor can diagnose dry eyes with comprehensive eye examination, by observing the flow and quality of tears and examination of the cornea and eyelids, while he is searching for following symptoms: redness, irritation, stinging pain or burning eyes, tearing or problems with contact lenses. (36)

“Dry eyes, with deficiency of tear production confirmed by the Schirmer test, need frequent applications of drops such as normal saline, Ringer-Locke solution or hypromellose, or more complex formulations which have polyvinyl alcohol in them, if the simpler remedies fail to help. For no very clear reason, it has been found that some patients are helped by the sealing of the lacrimal puncta. “ (2)

Figure 26 Schimer test with filter paper

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“The eyes are closed for a few minutes and taken out to measure the amount of tear production. The Schirmer’s test can determine if there is difficulty in tear production or if the tears are not efficient in maintaining eye health. Tears may also be examined to see if they contain enough moisture, proteins, and other materials.” (22) The most important factor of dry eye treatment is to find the cause of insufficient humidification. Sometimes this is not possible, because disorder which is causing the dry eye syndrome cannot be cured. For example, we can heal the pain of rheumatism, but there is no treatment for rheumatoid artritida. In some cases it is not possible to eliminate the cause of dry eye because we are taking special medications. (7)

Some patient can use artificial tears or similar eye drops, can help the eyes maintain tear production and guard against the staving off tear loss, and are usually good at relieving symptoms. The most common treatments for dry eyes include: restrictions drying - avoid worsening situations, such as overheated room, wind or smoke and wearing sunglasses outdoors. We can treat dry eye with a surgery. Dry eye syndrome may be treated with surgery to block the drainage tear ducts. This is either with temporary plugs or by permanently sealing the drainage hole. Both methods have a goal of maintaining tears which eye produces, for a long period of time. (7)

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10 Eye tests

“Basic eye examinations in general practitioner‘s practice include visual acuity in distance and near vision, visual field examination and orientation and color vision testing. The history of the patient is an important part of the examination, e.g. a focus on subjective problems suffered by the patient, factors such as injury and other symptoms (nausea, vomiting), that can be linked to eye diseases.” (23)

Medical history is an important part of the eye examination. First, we ask the patient what are the current problems and when the problems start. Family history is focusing on hereditary diseases - cataract, glaucoma, higher refractive errors, strabismus and congenital malformations. In the personal history we discover all the diseases from childhood, operation and medications. We focus mainly on diseases that may be related to an eye involvement (diabetes mellitus, hypertension). Basic investigative methods are objective and subjective. GPs must focus first on the general examination of both eyes. The basic methods of general examination are aspection and palpation. Subjective method are testing visual acuity for distance and near vision, test visual field (peripheral vision) and color vision on the Ishihara color test plate. (23)

We can find out refraction of the eye by two methods - subjectively and objectively. During the objective examination we examine visual acuity using the auto refractor and for subjective tests we are tuning the diopter value according to the patient's needs. (23)

10.1 Visual acuity

Visual acuity is given by the resolving power of the eye and its refractive status. Visual acuity is investigated by the charts. These tests are used for correction hypermetropia. Visual acuity tests are usually designed for either 5 or 6 meters. The most used visual test chart are Snellen eye chart and there are other visual test chart as Pflüger hooks, Landolt rings and children visual test chart. The optic acuity for near (myopia) is determined by a reading distance of 40 cm. Most commonly test chart for reading distance are Jaeger chart.”To evaluate your near vision, your eye doctor may use a small hand-held card called a Jaeger eye chart. The Jaeger chart consists of short blocks of text in various type sizes.” (24)

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Figure 27 Standard Snell Chart

10.2 The autorefractor

“The autorefractor takes an electronic measurement of how well your eyes focus and gives readout of your approximate prescription for the optometrist to use. If we do not have a record of your current prescription, the focimeter can read it from your glasses so that it can be compared with the findings of your eye examination by the optometrist.” (25)

Figure 28 The autorefractor “The optometrist fine-tunes his findings by asking you to read the test chart through different strength lenses. The results for one eye often vary from those for the other, so each eye will be tested individually before both eyes are finally tested together. The optometrist flips different

41 lenses in front of your eyes that change how clearly you can see. Depending on your answers, he changes the lenses until you have the clearest, most comfortable vision possible.” (25)

10.3 Pupillary reaction

Pupillary reactions can reveal a lot about the health of the eyes and of your body. The nerves that control the pupil travel through a long pathway within the body. Certain pupillary reactions can reveal neurological problems, including some serious conditions. Your pupil reactions are tested with a very bright light directed toward one or both of your eyes. Your doctor may focus on one eye or swing the light back and forth to study the ways your pupils change. (4)

10.4 Tonometry

Tonometry is the measurement of intraocular pressure using the devices. The principle of all instruments is based on the fact that with a certain pressure the cornea is deformed. The lower the intraocular pressure, the more the cornea is deformed under the same conditions, either pushed (Impression tonometry) or flatten (applanation tonometry). (4)

Figure 29 Applanation tonometry “Using a non-contact tonometer, the optical assistant (or the optometrist) blows a few puffs of air at each of your eyes in turn. The air bounces back at the instrument, giving a measurement of the pressure inside each eye. This is an important test, as high pressure can indicate the early stages of glaucoma, a sight-threatening condition.” (25)

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10.5 Perimetery

“Perimetery is examination of the viewing angle of the eye. It is performed so the patient is looking to mark in the front and indicates whether they see or not see the point of light that moves to the side. 1A visual field screener randomly flashes dots of light on a black background. If you fail to see any of the dots, this can be an indication of a blind spot.” (25)

Figure 30 A visual field screener

10.6 Cover tests

Cover tests helps us to detect strabismus, amblyopia or a decrease in depth perception. The cover test is a simple test in which the doctor asks us to fixate on a near or distant object. This test is performed to measure how well your eyes work together. (37)

Figure 31 Cover tests for tropias and phorias

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10.7 Retinoscope

“The optometrist may use an instrument called a retinoscope, which bounces a light beam off the back of your eye and back into the instrument. Different lenses focus the reflected light beam until it is steady, giving a close guide to the prescription you need. The retinoscope is very accurate - it is used to test the sight of very small children, or people with communication difficulties who can't easily describe how clearly they can see.” (25)

Figure 32 Retinoscope with ophtalmoscope “The optometrist uses an ophthalmoscope to examine the retina at the back of the eye, including the blood vessels and the front of the optic nerve. This important test can detect changes which can indicate diseases such as diabetes or high blood pressure. The optometrist darkens the room and sits quite close to you, while he shines a bright light into each eye in turn using the ophthalmoscope. The light may leave shadows on your vision, but these soon fade.” (25)

The slit lamp

“The slit lamp is a powerful, illuminated microscope that is used to examine the outer surface of your eyes - the cornea, the iris and the lens - to check for abnormalities or scratches. This is a very important test for contact lens wearers.” (25) It consists of three parts, lighting system, and magnifying system for observation and mechanical parts, which allows us to set the device into the optimal position for the investigation. (4)

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11 Strabismus

Strabismus is a condition when the two eyes do not look at the same direction, and therefore do not look at the same object at the same time. The condition is more commonly known as „lazy eye“. It typically involves a lack of coordination between the extra ocular muscles, which prevents bringing the gaze of each eye to the same point in space and proper binocular vision, which may adversely affect depth perception. (38)

Six different muscles surround each eye and work „as a team” so that both eyes can focus on the same object. Someone having strabismus, these muscles do not work together. Mobility of eye is performing by six extra ocular muscles - four straight and two oblique. The eye may be crossed or divergent from birth, or may become so later in life. (38)

“The deviation in direction of gaze of the two eyes is most commonly in the horizontal plane, usually convergent – esotropia- the two eyes being turned towards each other, and if one eye is persistently deviating it appears to be turned in towards the nose. In the less frequent cases of divergent squints – exotropia- the eyes are turned away from each other and one eye looks as if it is turned outwards. Vertical deviations-hypertropia- are comparatively rare. Whatever the direction of the strabismus, it is important to differentiate between those that arise in childhood and those that originate in later life.” (2)

Esotropia occurs after the second year of life. It tends to be hereditary. Esotropia is the result of convergence associated with accommodation which is forced by a hypermetropic child. The treatment presents a prescription with constant wearing full correction and at the same time a treatment of amblyopia. Exotropia is less common than esotropia, but its occurrence is increasing with age. It tends to be hereditary. Intermittent exotropia occurs between 1 to 5 years of age. Treatment is surgical-weakening of external or internal strengthening muscles. Constant exotropia is a congenital or is progression of intermittent exotropia. Treatment is the surgery. (5)

Hypertropia is a condition when one eye is higher than the other. The causes are congenital anomalies, trauma and CNS which disrupt the function of the upper oblique muscle. If there is a rise after the 6th years of age, is it usually called diplopia. Conservative treatment is prescription of prismatic glasses or occlusion on one eye. For the remaining defects it is

45 recommended to approach to surgery of oblique muscles. Heterophoria symptoms are occasional diplopia; it is a feeling of uncomfortable vision, fatigue, pain behind the eye and blurred vision. To finding the problem it will help us cover test and examination with prisms. The treatment is prescription with prismatic correction, modification and near correction and in complicated cases it is surgery. (5)

FigureFigure 33 Types of strabismus As with other binocular vision disorders, the primary therapeutic goal for those with strabismus is comfortable, single, clear, normal binocular vision at all distances and directions of gaze. Whereas amblyopia, if minor and detected early can often be corrected with use of an

46 eye patch on the dominant eye. The use of eye patches is unlikely to change the angle of strabismus.(38)

Advanced strabismus is usually treated with a combination of eyeglasses, vision therapy and surgery. Surgery does not change the vision. It change the position of one or more of the extra ocular eye muscles and it is frequently the only way to achieve cosmetic improvement. Glasses affect the position by changing the person’s reaction to focusing. Prisms change the way light and therefore images strike the eye simulating a change in the eye position. Early treatment of strabismus and amblyopia in infancy can reduce the chance of developing amblyopia and depth perception problems. Most children eventually recover from amblyopia by around age of 10, if they have had the benefit of patches and corrective glasses. (5)

Figure 34 Eye patches for adults and for children

Figure 35 Eye patch for spectacles

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12 Glasses

Spectacles (glasses, eyeglasses) are the oldest and best established of all the refractive options. Glasses are a set of two glasses or plastic lenses in a frame, worn in front of the eyes to improve the clarity of the eyesight. Spectacles do not only affect your vision but also your appearance. Glasses are made individually for each of us. Frames are produced from a range of materials such as plastic, titanium, steel. Under the term spectacle frame we understand a frame consisting of frame front and temples. The frame front includes rims that hold the lenses and a bridge across the top of the nose. The bridge sits over the nose and supports most of the weight of the glasses. Temples are the frame parts that curve behind the ears to hold the glasses on your face. (45)

Figure 36 Description of glasses

12.1 Types of frames

We have three different types of frames: full rimmed glasses, half rimmed glasses and rimless glasses. These types are most used for correction. Other types of glasses are used for another purpose for example: swimming, working with harmful materials or for entertainment. (39)

Full rimmed glasses - lenses are being secured inside of frames which encircles the lens. This is the only type of glasses when we can insert a mineral lens. (39)

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Figure 37 Plastic full rimmed frame Half rimmed glasses- glasses have a frame which only partially encircles the lenses (commonly the top portion), which are held in place most often by high strength nylon wire. Mineral glass is a fragile material in which it is not possible to create a groove, so we need to choose a plastic lens for correction. (39)

Figure 38 Half rimmed glass Rimless glasses- have no rim and are therefore lightweight. The bridges and temples are attached directly to the lens with screws. This type of frame is very sensitive to improper handling and it is necessary to take off glasses with both hands and put them into a hard case. In this case we choose a plastic lenses for correction, the best material for this type of frame is Trivex. (39)

Figure 39 Rimmless glasses

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In the choice of spectacle frames it is important to think about people who have allergies. In the case of allergy to metal it is suitable to choose titanium material for frames - nickel-free metal. Nickel is the most common component of metal that causes allergy. If someone has allergies to fabric softeners in plastics frames, we need to choose a metal frame. In the selection of frame colors we need to consider skin tone, hair color, but also the color scheme of our clothing and jewelry. (40)

Safety glasses protect the eyes from harm by either mechanical or radiation or heat. Diving goggles and sunglasses for sports like for swimming they separate eyes from the aquatic environment and they protect eyes and they provide a sharp vision. Ski goggles protect eyes against the cold airflow and from snow. Sunglasses are actually glasses which have shaded lens to protect the eyes from bright sunlight; they are often used during sunbathing (in the summer or on the beach by the sea). Special glasses are used for watching 3D movies or drawings or for creating a sense of virtual reality. This can be achieved by different colors of glass. They have one red lens and one blue or cyan lens or similar color filter. (40)

12.2 Materials for glasses

The material identifies properties of spectacle frame. We distinguish two groups of materials - non-metallic spectacle frames and metal frame. The most common materials for production of frames are plastics and metal alloys. Main materials for production of non-metallic frames: natural materials (wood, leather, horn, etc.), celluloid - cellulose nitrate, cellulose acetate, polymethyl methacrylate and optyl. Between the most frequently used materials for production of metal frames they are alloys of copper, nickel and zinc. A large part of population is allergic to nickel, so instead of that we use alloy steel and titanium. There are also other materials like brass, pewter, bronze, platinum, gold, silver and more. (45)

“We have other types of spectacles for example for single vision, bifocal, trifocals or progressive lens. There are single prescription spectacles. Standard single vision spectacles are made up with the „distance“ prescription. „Reading glasses „ are single vision lenses made up with the „reading“ or near prescription and they are one of the options in presbyopia. Bifocal lenses are corrective lenses with two distinct regions of differing optical power enabling refractive correction for two different focal distances in the same set of glasses, usually distance and reading, but may be intermediate, e.g. for VDU (visual display unit) use.

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Trifocals are similar to bifocals but contain three distance optical regions, enabling three different focal distances (distance, intermediate, and near) in the dome set of glasses. Occasionally used in the hospital eye service. In progressive lenses the positive refractive power gradually increases throughout the surface of the lens resulting in an intermediate corridor and a reading area at the bottom of the lens.” (1)

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13 History of glasses

There was no optical help in the form of glasses in the ancient world. The Roman Emperor Nero used a polished emerald in front of his eyes during the gladiator fights. It was probably because of its green color and because emerald can filter sunlight. Apparently he had bad eyesight and therefore he used the emerald. The first evidence of using the corrective help dates back to approximately the year 4 B.C. It was a ball filled with water which could provide magnification. With its help the Roman tragic poet Seneca read all the books. For further research will have to move to the middle Ages. The first pair of lenses planted into the frame was done by Chinese probably in 10th century. At the same time there was an effort for vision correction in medieval Europe but the result was different. They invented so-called "reading stones" which were made around 1000 AD in Venice. (43)

Figure 40 Reading stone In the 13th century the English thinker and philosopher Roger Bacon described reading stone in his book Opus Maius (1267). He explained that old people can see the letters sufficiently large with use of reading stone. This knowledge is very important because it was the first step to creating spectacles. First description of the glasses was in Italy around 1289. In Italian aristocracy glasses were popularized by Florentine person named Salvino D’Armate. The Italian claimed that he is an inventor of spectacles. The first known artistic work with glasses appears in 1352 by Tommaso di Modena. Concave lenses (suitable for short-sighted) appears in the 16th century. Pope Leo X was using them because he was very nearsighted.(44)

According to oldest reports and paintings spectacles frames were made of bones. Later they began to use other materials - iron, silver, gold, horn, skin or shell. It was impossible to put

52 them on the nose but with the help of hand it was possible to hold them by the handle in front of the eyes. The name "spectacles" is probably derived from beryl. Beryl was used for grinded spectacle lenses. Beside transparent beryl it was also used quartz. Optical glass was invented a long time after that and eventually plastic lenses were invented, which are lighter and not as fragile as glass lenses. (42)

The inventors of spectacles have been trying to solve the problem of the right setting of glasses since the invention of glasses, both from the perspective of mechanics and optics. It took them 350 years. Back in the 17 century Spanish makers were trying to solve the problem with silk ribbons which were attached to the frames with a ribbon forming a loop around the ears. Finally, in 1730 a London optician Edward Scarlett presents solid temples. Temples has support by the upper part of the ear to hold the glasses on your face. This method was quickly spread to the whole Europe. But already in 1752, there is another invention of temples. James Ayscough invented temples which are allowed to bend. The popularity of these spectacles was huge and they appeared in all kinds of paintings. They spread very quickly although it wasn't a cheap thing. (41)

Figure 41 Spectacles with temples Despite all these improvements around 1800 many aristocratic Frenchmen and Englishmen wore spectacles only in private. For higher class it was humiliating to wear spectacles. If they had to wear them in the public they were using the so-called monocle. "Spectacles" on one eye were developed in Germany around 1700. Monocle was not so noticeable; it was small and easier to hide. After the World War I popularity of monocle went down because of their connection with German inventor. (43)

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Figure 42 Monocle Benjamin Franklin discovers the bifocal lenses in 1780. Bifocal lenses are lenses with dual focal length. Spectacles with bifocal lenses have replaced normal glasses for two visions into one pair. Although they have a great advantages a permanent use of bifocal lenses started later in 19 century. In 1827 trifocal lenses was patented by John Isaac Hawkins. Bifocal lenses were cemented to 2 parts, they were fragile, unsightly and in the point of connection they were many dirty spots. Borsch invented a new thing for bifocal lenses for better purpose. Bifocal lens was a combination of both lenses (distance and near) melted into one lens. He patented his invention in 1908. (42)

Figure 43 Bifocal spectacles “The lorgnette, two lenses in a frame which the user held by a side handle, was another 18th century development (by Englishman George Adams). The lorgnette probably developed from the scissors-glass, which was a double eyeglass on a handle. Since the two branches of the handle came together under the nose and looked as if they were about to cut it off, they were known as binocles-ciseaux or scissors glasses. The English changed the size and form of the scissors-glasses and produced the lorgnette. The frame and handle were frequently artistically embellished, since they were used mostly by women and more often as a piece of jewelry than as a visual aid. The lorgnette maintained its popularity with ladies of fashion,

54 who would not wear spectacles. The lorgnette was still popular at the end of the 19th century.” (26)

Figure 44 Lorgnette from 14 carat gold Spectacles become very fashion accessories at the 20.century. In the thirties there was so much wider selection of different frames. For glasses there was also some kind of fashion trend. One time it was so popular to wear spectacles like John Lennon or Harry Potter. Also sunglasses were very popular in the thirties. At this time we still use spectacles for correction but they are being slowly replaced by contact lenses and laser surgery. Spectacles still remain an irreplaceable and important protective piece of equipment. (42)

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Závěr

Tato práce si kladla za cíl předložit ucelený soubor témat pro oční optiky, které se týkají očních onemocnění, problematiky kontaktních čoček, ale i informací o brýlích a jejich historii. A v neposlední řadě i technologické problematiky brýlových čoček.

Čerpala jsem z mnoha různých materiálů, které byly značně různorodé po stránce jazykové úrovně i „logického“ a věcného uspořádání. Bylo potřeba používat jak překladových tak výkladových slovníků, inspirovat se již publikovanými odbornými materiály jak v českém tak v anglickém jazyce. Některá témata obsahují mnoho odborných výrazů, protože se jedná vysloveně o lékařskou problematiku. U těchto témat nešlo pozměnit jejich odborné výrazy, jelikož se nelze odchýlit od daných medicinských faktů neboli výrazů. Někde mohl být text naopak obecnější, s použitím běžných výrazů.

Bylo potřeba vhodně sjednotit formu všech uvedených témat tak, aby byl oční optik schopen se v této problematice sám orientovat a komunikovat jak s odborníky z profese, tak např. i se zákazníky, kteří zavítají do oční optiky. Často je totiž nutné poradit zákazníkovi s jeho zrakovými problémy, se kterými se potýká v běžném každodenním životě. Zvláště v dnešní době se často může stát, že zákazník bude anglicky mluvící, proto je velmi vhodné a žádoucí, aby byl oční optik schopen s tímto zákazníkem komunikovat a vyhovět jeho požadavkům. K tomu může optikovi posloužit předložený soubor anglických textů, které jsou srozumitelné, se stejnou jazykovou úrovní a textovou výstavbou.

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Seznam použité literatury a zdrojů informací

Literatura

1. DENNISTON, Alastair K a Philip I MURRAY. Oxford handbook of ophthalmology. 2nd ed. New York: Oxford University Press, 2009. ISBN 01-995-5264-9 2. ABRAMS, David. Ophtalmology in Medicine : An Illustrated Clinical Guide. 1. vyd. London: Martin Dunitz, 1990. ISBN 0-8016-00286. 3. HYCL, Josef. Oftalmologie: minimum pro praxi. Vyd. 1. Praha: Triton, 1999, 111 s. Levou zadní. ISBN 80-725-4065-3. 4. KRAUS, Hanuš. Kompendium očního lékařství: minimum pro praxi. 1. vyd. Praha: Grada Publishing, 1997, 111 s. Levou zadní, sv. 43. ISBN 80-716-9079-1. 5. ŘEHÁK, Svatopluk. Oční lékařství: Učebnice pro lékařské fakulty. Brno: Avicentrum, 1989. ISBN 08-033-89. 6. SLEZÁKOVÁ, Lenka. Ošetřovatelství pro zdravotnické asistenty IV: dermatovenerologie, oftalmologie, ORL stomatologie. 1. vyd. Praha, 2008, 213 s. ISBN 978-802-4725-062. 7. HYCL, Josef a Lucie TRYBUČKOVÁ. Atlas oftalmologie. Praha: Triton, 2008, 239 s. ISBN 978-807-3871-604. 8. AUTRATA, Rudolf a Jana VANČUROVÁ. Nauka o zraku. Brno: Institut pro další vzdělávání pracovníků ve zdravotnictví v Brně, 2002, 226 s. ISBN 80-701-3362-7. 9. PASSWORD anglický výkladový slovník s českými ekvivalenty. Praha, 1991. ISBN 80- 204-0288-8. 10. Anglicko-český, česko-anglický slovník. 1. vyd. Praha: FIN Publishing, 2005, 719 s. ISBN 80-860-0281-0.

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Časopisy

11. Brýle a Móda: Společenský a odborný magazín. 2012, roč. 2, č. 1, s. 22-23. DOI: ISSN 1804-7866. 12. Brýle a Móda: Společenský a odborný magazín. 2012, roč. 2, č. 2, s. 16-18. DOI: ISSN 1804-7866. 13. Brýle a Móda: Společenský a odborný magazín. 2013, roč. 3, č. 1, s. 38-39. DOI: ISSN 1804-7866. 14. Brýle a Móda: Společenský a odborný magazín. 2013, roč. 3, č. 3, s. 36-39. DOI: ISSN 1804-7866.

Internetové zdroje

15. Cataracts. Symptom Checker, Health Information and Medicine Guide [online]. [cit. 2014-04-08]. Dostupné z: http://www.patient.co.uk/health/cataracts 16. A Myriad of Lens Options. About.com [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://vision.about.com/od/eyeglasses/p/Lens_options.htm 17. Lens Materials. Dr. Travel [online]. [cit. 2014-04-08]. Dostupné z: http://www.drtavel.com/lens-materials 18. Inflammatory Eye Diseases. Eye Surgeons Associates [online]. [cit. 2014-04-08]. Dostupné z: http://www.eyesurgeonspc.com/bettendorf/inflammatory-eye- diseases.htm. 19. Eye Inflammation. NativeRemedies [online]. c 1997-2014 [cit. 2014-04-08]. Dostupné z: http://www.nativeremedies.com/ailment/eye-inflammation-symptoms.html 20. Keratitis Definition. Mayo Clinic [online]. c 1998-2014 [cit. 2014-04-08]. Dostupné z: http://www.mayoclinic.org/diseases-conditions/keratitis/basics/definition/con- 20035288 21. Travel Tools and Techniques of People Who are Blind or Who Have Low Vision. Accessible Pedestrian Signals [online]. [cit. 2014-04-08]. Dostupné z: http://www.apsguide.org/chapter2_travel.cfm 22. Dry Eyes. Eye Health Web: Healthy vision for healthy life [online]. c 2014 [cit. 2014- 04-08]. Dostupné z: http://www.eyehealthweb.com/dry-eyes/ 23. Základní oční vyšetření a terapie v praxi praktického lékaře. Medicína pro praxi [online]. 2012, 6-7 [cit. 2014-04-08]. Dostupné z: http://www.medicinapropraxi.cz/pdfs/med/2012/06/08.pdf

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24. SEGRE, Liz. The Eye Chart and 20/20 Vision. All About Vision [online]. c 2000-2014 [cit. 2014-04-09]. Dostupné z: http://www.allaboutvision.com/eye-test/ 25. The Specsavers guide to your eye examination. Specsavers Opticians [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www.specsavers.co.uk/eye-health/eye-test 26. D. DREWRY, Richard. What Man Devised That He Might See. Teagle Optometry [online]. c 2007 [cit. 2014-04-08]. Dostupné z: http://www.teagleoptometry.com/history.htm) 27. Symptoms of Open-Angle Glaucoma. Glaucoma Research Foundation [online]. [cit. 2014-04-08]. Dostupné z: www.glaucoma.org 28. Brýlové čočky. A.S.O.P Optik [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www.asop-optik.cz/4698/brylove-cocky/ 29. Tórické kontaktní čočky. Tórické kontaktní čočky [online]. [cit. 2014-04-08]. 30. Dostupné z: http://www.toricke-kontaktni-cocky.cz/e-cocky/ 31. Bifokální KČ. Kontaktní čočky: Učební texty pro studium optometrie [online]. [cit. 2014-04-08]. Dostupné z: http://is.muni.cz/do/1499/el/estud/lf/ps09/cocky/web/pages/str05.html 32. Bifocal and Multifocal Contact Lenses. All About Vision [online]. c 2000-2014 [cit. 2014-04-08]. Dostupné z: http://www.allaboutvision.com/contacts/bifocals.htm 33. Zánět oka. Vše o očích a korekci zraku [online]. c 2009-2014 [cit. 2014-04-08]. Dostupné z: http://www.videni.cz/nemoci-oci/zanet-infekce/68-zanet-oka 34. Oční infekce a vady. Abeceda zdraví [online]. c 2005-2013 [cit. 2014-04-08]. Dostupné z: http://www.abecedazdravi.cz/nemoci/ocni-infekce-a-vady 35. Zánět spojivek. Vitalion [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://nemoci.vitalion.cz/zanet-spojivek/ 36. Suché oko. Baush & Lomb [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www.bausch.cz/cs-cz/péče-o-zrak/infekce-a-podráždění-očí/suché-oko/ 37. Eye examination. In: Wikipedia: the free encyclopedia [online]. San Francisco (CA): Wikimedia Foundation, 2001- [cit. 2014-04-08]. Dostupné z: http://en.wikipedia.org/wiki/Eye_examination 38. MedicinePlus [online]. 26.2.2014 [cit. 2014-04-08]. Dostupné z: http://www.nlm.nih.gov/medlineplus/ency/article/001004.htm 39. Jaké brýle vybrat. Optika Richter [online]. c 2010 [cit. 2014-04-08]. Dostupné z: http://www.optika-richter.cz/dioptricke-bryle/jake-bryle-vybrat/

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40. Brýlové obruby. Vše o očích a korekci zraku [online]. c 2009-2014 [cit. 2014-04-08]. Dostupné z: http://www.videni.cz/bryle/brylove-obruby http://cs.wikipedia.org/wiki/Brýle 41. Historie brýlí. Oční optik Rudolf Vrzal [online]. [cit. 2014-04-08]. Dostupné z: http://optikvrzal.wz.cz/main.php?odkaz=7&stranka=historie 42. Kde se vzaly brýle?. Pohodová žena [online]. [cit. 2014-04-08]. Dostupné z: http://www.pohodovazena.cz/3401/kde-se-vzaly-bryle/ 43. Historie brýlí a brýlových čoček. Pan Optika [online]. c 2012 [cit. 2014-04-08]. Dostupné z: http://pan-optika.cz/historie-bryli-a-brylovych-cocek-1006/ 44. I brýle mají svou historii. FiftyFifty [online]. c 2005-2014 [cit. 2014-04-08]. Dostupné z: http://www.fiftyfifty.cz/I-bryle-maji-svou-historii-4093471.php 45. Brýle. In: Wikipedia: the free encyclopedia [online]. San Francisco (CA): Wikimedia Foundation, 2001-2014 [cit. 2014-04-10]. Dostupné z: http://cs.wikipedia.org/wiki/Br%C3%BDle

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Zdroje obrázků

Tabulka č.1 DENNISTON, Alastair K a Philip I MURRAY. Oxford handbook of ophthalmology. 2nd ed. New York: Oxford University Press, 2009. ISBN 01-995-5264-9, str. 738

Obrázek č.1 What Is Astigmatism?. Tokyo optician [online]. [cit. 2014-04-08]. Dostupné z: http://tokyooptician.com/astigmatism.php

Obrázek č.2 Effective Presbyopia Treatment Using Lasik. Singapore Online Business [online]. [cit. 2014-04-08]. Dostupné z: http://www.onlinebusiness.sg/effective-presbyopia- treatment-using-lasik/

Obrázek č.3 Computer Vision Syndrome (CVS). Vision Care Center [online]. c 2012 [cit. 2014-04-08]. Dostupné z: http://www.bartelsvisioncare.com/eye-disorders/computer-vision- syndrome-cvs/

Obrázek č.4 Cataracts. Ophthalmic Consultants of Rockland [online]. c 2014 [cit. 2014-04- 08]. Dostupné z: http://www.ocreyemd.com/eyeconditions/cataracts/ Obrázek č.5 Cataracts. The eye specialists center [online]. 2014 [cit. 2014-04-08]. Dostupné z: http://www.eyespecialistscenter.com/detection-treatments/cataracts.html

Obrázek č.6 Cataract surgery. Riverside [online]. c 1995-2014 [cit. 2014-04-08]. Dostupné z: http://www.riversideonline.com/health_reference/Eye/EY00014.cfm

Obrázek č.7 Cataract surgery. Riverside [online]. c 1995-2014 [cit. 2014-04-08]. Dostupné z: http://www.riversideonline.com/health_reference/Eye/EY00014.cfm

Obrázek č.8 Glaucoma care. Orion Eye [online]. c 2012 [cit. 2014-04-08]. Dostupné z: http://orioneyecenter.com/glaucoma-care/

Obrázek č.9 Products. Green vision optical glasses co.,ltd [online]. c 2010-2012 [cit. 2014- 04-08]. Dostupné z: http://www.gvioptical.com/ProductShow.asp?ArticleID=533

Obrázek č.10 Reversacol Applications. Vivimed [online]. [cit. 2014-04-08]. Dostupné z: http://www.vivimedlabs.com/vivimed-products/reversacol-photochromic-dyes/reversacol- applications

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Obrázek č.11 Mineral Bifocal Lens. HIWTC - The Successful Place Of Manufacturers & Exporters [online]. c 1998-2013 [cit. 2014-04-08]. Dostupné z: http://www.hiwtc.com/products/mineral-bifocal-lens-197156-8094.htm

Obrázek č.12 Are you using the right spectacle lens?. Optika optometrist [online]. c 2013 [cit. 2014-04-08]. Dostupné z: http://optikaoptometrist.com.my/are-you-using-the-right-spectacle- lens /

Obrázek č.13 What Every Contact Lens Wearer Needs To Know (But Is Afraid To Ask). The Huffington Post [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www.huffingtonpost.com/2013/09/26/contact-lens-hygiene-questions-answers-eye- health_n_3950593.html Obrázek č.14 Bifocal and Multifocal Contact Lenses. All about vision [online]. c 2010-2014 [cit. 2014-04-08]. Dostupné z: http://www.allaboutvision.com/contacts/bifocals.htm

Obrázek č.15 Péče o kontaktní čočky je snadná?. Brýle a móda: Společenský a odborný magazín. 2013, roč. 3, č. 1, s. 3. ISSN 1804-7866.

Obrázek č.16 Péče o kontaktní čočky je snadná?. Brýle a móda: Společenský a odborný magazín. 2013, roč. 3, č. 1, s. 3. ISSN 1804-7866.

Obrázek č.17 ABRAMS, David. Ophtalmology in Medicine : An Illustrated Clinical Guide. 1. vyd. London: Martin Dunitz, 1990. ISBN 0 8016 00286.

Obrázek č.18 Keratitis (Corneal Ulcers). Johns Hopkins Medicine [online]. [cit. 2014-04-08]. Dostupné z: http://www.hopkinsmedicine.org/wilmer/conditions/keratitis.html

Obrázek č.19 ABRAMS, David. Ophtalmology in Medicine : An Illustrated Clinical Guide. 1. vyd. London: Martin Dunitz, 1990. ISBN 0 8016 00286

Obrázek č.20 Stye. Active forever [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www.activeforever.com/a-stye

Obrázek č.21 Trachom. Světlo pro svět [online]. c 2010 [cit. 2014-04-09]. Dostupné z: http://www.svetloprosvet.cz/cs/jak-pomahame/podporovane-projekty/trachom/

Obrázek č.22 Braille - Design considerations for the visually impaired. Bold post [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://boldpost.leibold.com/2011/08/design- considerations-for-the-visually-impaired/ /

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Obrázek č.23 Disability Awareness Month and White Cane Awareness Day. Lighthouse for the Visually Impaired and Blind [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www1.lvib.org/2010/10/01/disability-awareness-month-and-white-cane-awareness-day/

Obrázek č.24 Dogs With Jobs. National geographic [online]. c 1996-2014 [cit. 2014-04-08]. Dostupné z: http://kids.nationalgeographic.com/kids/photos/dogs-with-jobs/#/seeing-eye- dog_15440_600x450.jpg

Obrázek č.25 ABRAMS, David. Ophtalmology in Medicine : An Illustrated Clinical Guide. 1. vyd. London: Martin Dunitz, 1990. ISBN 0 8016 00286

Obrázek č.26 ABRAMS, David. Ophtalmology in Medicine : An Illustrated Clinical Guide. 1. vyd. London: Martin Dunitz, 1990. ISBN 0 8016 00286

Obrázek č.27 Standard Snells Chart - Essential Steps in Patient's Eye Examination. YOUNG DOCTORS' RESEARCH FORUM [online]. c 2011 [cit. 2014-04-08]. Dostupné z: http://medilinks.blogspot.cz/2012/01/essential-steps-in-patients-eye.html

Obrázek č.28 Autorefraktometr. Čočky [online]. [cit. 2014-04-08]. Dostupné z: http://www.cocky.cz/autorefraktometr.html

Obrázek č.29 ABRAMS, David. Ophtalmology in Medicine : An Illustrated Clinical Guide. 1. vyd. London: Martin Dunitz, 1990. ISBN 0 8016 00286

Obrázek č.30 Equipment. Glaucoma Consultants [online]. [cit. 2014-04-08]. Dostupné z: http://www.glaucomaconsult.net/practice_facility.php

Obrázek č.31 Ocular Motility Tests[Cover Tests & Subjective ClinicalMethods. MediacalGeek [online]. [cit. 2014-04-08]. Dostupné z: http://www.medicalgeek.com/lecture- notes/1736-ocular-motility-tests-cover-tests-subjective-clinicalmethods.html

Obrázek č.32 Streak Retinoscope, with Ophthalmoscope. Nanjing Redsun Optical Co. [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://redsunhyq.en.made-in- china.com/product/MXnxQyPbaacW/China-Streak-Retinoscope-with-Ophthalmoscope- YZ24D-.html

Obrázek č.33 Eyes Point in Different Directions (Strabismus). Summit Medical GROUP [online]. c 2013 [cit. 2014-04-08]. Dostupné z: http://www.summitmedicalgroup.com/library/pediatric_health/oph_strabismus/

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Obrázek č.34 Orthoptic Eye Patches. 3M [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://solutions.3m.com/wps/portal/3M/en_EU/Healthcare-Europe/EU- Home/Products/ProductCatalogue/?PC_Z7_RJH9U52300PI40IA1Q602S28E7000000_nid=C VV9S6LHLLbe00N2PSDXLHgl

Obrázek č.35 Látkové okluzory. Okluzory pro děti [online]. c 2014 [cit. 2014-04-08]. Dostupné z: http://www.okluzoryprodeti.cz/products/107-okluzor-na-bryle-kocka.aspx

Obrázek č.36 Spectacles Repair & Services. Nationwide Frame Repairs [online]. [cit. 2014- 04-08]. Dostupné z: http://www.nfr.co.uk/en/spectacles-repair/

Obrázek č.37 Tom Ford eyeglasses. Polyvore [online]. [cit. 2014-04-08]. Dostupné z: http://www.polyvore.com/tom_ford_eyewear_full_rim/thing?id=59913328

Obrázek č.38 Eye Facts: Reading Glasses And Aging. The Zenni Blog [online]. [cit. 2014-04- 08]. Dostupné z: http://blog.zennioptical.com/eye-facts-reading-glasses-and-aging/

Obrázek č.39 Gold & Wood A14 Rimless Eyeglasses. AskMen [online]. [cit. 2014-04-08]. Dostupné z: http://www.askmen.com/fashion/accessories/gold-wood-a14-rimless- eyeglasses.html

Obrázek č.40 The History of Eyeglasses. Spydersden [online]. [cit. 2014-04-08]. Dostupné z: http://spydersden.wordpress.com/2012/03/04/the-history-of-eyeglasses/

Obrázek č.41 Eyeglasses and Spectacles. American Optometric Association [online]. c 2014 [cit. 2014-04-08]. Dostupné z: https://www.aoa.org/about-the-aoa/archives-and- museum/museum-collections/eyeglasses

Obrázek č.42 Monocle Glass and Brass with Gold Chain. Gilai Collectibles [online]. c 1999- 2014 [cit. 2014-04-08]. Dostupné z: http://www.gilai.com/product_1219/Monocle-Glass-and- Brass-with-Gold-Chain

Obrázek č.43 History of Optometry. History of Optometry [online]. [cit. 2014-04-08]. Dostupné z: http://fs.aoa.org/optometry-archives/optometry-timeline.html

Obrázek č.44Antique 14 Karat Gold lorgnette. One of a kind antiques [online]. c 1995-2014 [cit. 2014-04-08]. Dostupné z: http://oneofakindantiques.com/product/2693/Antique-14- Karat-Gold-lorgnette-1.htm

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