11 November 2010 lp_1 21/10/2010 13:48 Page 1 dispensingoptics Dispensing Optics PO Box 233, Crowborough TN6 9BD Telephone: 01892 667626 Fax: 01892 667626 Email: [email protected] November 2010 Website: www.abdo.org.uk 11 November 2010 lp_1 21/10/2010 13:48 Page 2 11 November 2010 lp_1 21/10/2010 13:48 Page 3 3 dispensingoptics CONTENTS November 2010 3 Cover point by Tony Garrett Cover point 4 Continuing Education and Training Have you ever tried a trifocal? by Anthony Blackman 8 Frequently asked questions suffered by our contact lens opticians by Kim Devlin of having to gain 50 per cent more points than any other registrant is 10 ABDO Conference and finally to be corrected. From the next Exhibition 2010 CET cycle they will only be required to Changes, challenges and gain 36 points like everybody else. achievements at ABDO 2010 by Nicky Collinson These are two fundamentally important changes which address the 16 Patient and practice real concerns of many ABDO management GOC offers changes members. We have campaigned hard Creating a marketing strategy It is no secret that we at ABDO have on these issues and we have been by Antonia Chitty been fiercely critical of the GOC in particularly well supported by past recent years over a number of issues. It president James Russell who, as a 18 Optician Index August 2010 summary is therefore very pleasing to be able to member of GOC, has spoken so report on two very significant passionately on behalf of registrants. proposals being put forward. 20 BCLA news Conference 2010 Be aware of risks, says BCLA First of all our concern over the effect This year’s conference, held against President of retention fees on part-time low the backdrop of these difficult by Nicky Collinson More to membership than meets wage earners has been addressed by economic times, could have been the eye the proposed introduction of a lower hard to fill. Instead we had a sell out by Vivien Freeman band for those affected whether they gala dinner of over 350 and over 550 be dispensing opticians or people registered for the exhibition optometrists. and or CET. It was a first class event 22 Newsbrief and I have had many messages from Secondly, the long running injustice members, guests and exhibitors, all of 32 Disjointed jottings from whom have spoken in glowing terms a DO’s desk . about the atmosphere and vitality of Customer evaporation is a very slow the event. Elaine Grisdale, Michael leak Potter and our partners at Event by Chris Hunt Exchange pulled out all the stops for a very memorable weekend. And, for 33 Book review the first time, the bookings for the Doing a Literature Review in conference, accommodation and Health and Social Care: A Practical dinner were managed in-house, by Guide Katie Docker and the Membership Department team. A remarkable 34 CET answers achievement at a busy time for them. The measurement of spectacle lens power - part two Tony Garrett n 35 Diary of Events Front cover: ABDO actively works in Inside the AR Coating conjunction with: chamber at the Signet Armorlite Kodak CleAR Lens laboratory The Worshipful Company of Spectacle Makers 11 November 2010 lp_1 21/10/2010 13:48 Page 4 4 dispensingoptics November 2010 Have you ever tried a trifocal? By Anthony Blackman CompetencIes covered: Optical appliances Target group: Dispensing opticians, optometrists During their training, all dispensing increasing age the range achieved advantages and disadvantages, opticians (DOs) learn about trifocals, with a single addition (on top of any which are, briefly, as follows. but how many DOs have actually distance prescription) reduces. When dispensed a pair, either to an existing a patient reaches their mid-fifties, a Single vision intermediate spectacles wearer, or, even rarer, to a first time mid-range gap forms between the will provide the greatest field of view, wearer? distance prescription’s range and the and can be calculated to offer near portion’s range. Therefore a accurate intermediate corrections The next few pages will: second, weaker add is needed to fill (the amplitude of accommodation • give a reminder of an old style of this mid-range gap and restore and working distance being required). lens, continuous clear vision. Most However the wearer will only be able • explain the principles behind conveniently this is as a trifocal or to use the spectacles for tasks at trifocals, progressive lens, but other options are intermediate distances, and they will • show what is still available to DOs, available. An examination of the give poor distance vision and difficulty • show why they should not be suppliers' catalogues shows that the with small print close to them. ignored as an option for vision availability of trifocals starts with a near correction. add of +1.50D, which is about right for There are two bifocal options which a typical patient in their mid-fifties. have the advantage of providing Hopefully the reader will gain some clear vision in the intermediate and useful information and be more aware The spectacle lens options available to either the distance or near range. This of their usefulness. fill this intermediate gap are: is certainly more convenient than • Single vision intermediate single vision intermediate spectacles; Age, amplitude of spectacles but will still leave older presbyopes accommodation and range • Bifocals (either distance/ unable to see clearly for some tasks. As DOs we know that when patients intermediate or intermediate/near) reach their forties they will become • Trifocals This brings us to the progressive presbyopic and will need a • Progressives options. Progressive lens designs have prescription for near work in the form • Enhanced readers improved immensely over the years, of a reading addition (add). The add • Occupational Progressive Addition with each new generation offering will restore the near range of clear Lenses (OPALS) wider fields of clear vision, particularly vision which they had in their youth. As for distance and near. The shown in Table 1 and Figure 1, with All of the above options have their intermediate area was rather limited in This article has been approved for 1 CET point by the GOC. It is open to all FBDO members, including associate member optometrists. Insert your answers to the six multiple choice questions (MCQs) online at www.abdo.org.uk, or on the answer sheet inserted in this issue and return by 16 December 2010 to ABDO CET, Courtyard Suite 6, Braxted Park, Great Braxted, Witham CM8 3GA OR fax to 01621 890203. If you complete online, please ensure that your email address and GOC number are up-to-date. The pass mark is 60 per cent. The answers will appear in our January 2011 issue. C-13053 11 November 2010 lp_1 27/10/2010 10:26 Page 5 Continuing Education and Training Age Add(D) WD(cm) Range★(cm) +0.50 40 200 to 29 45 +1.00 35 100 to 25 +1.25 30 80 to 24 +1.00 40 100 to 33 50 +1.50 35 67 to 29 +2.00 30 50 to 25 +1.50 40 67 to 33 55 +2.00 35 50 to 29 +2.25 30 44 to 27 +1.75 40 57 to36 60 +2.25 35 44 to 31 +2.75 30 36 to 27 +2.50 40 40 to 33 70 +3.00 35 33 to 29 +3.75 25 27 to 24 Table 1: Range of clear vision for some ages, adds and working distances Figure 1: Range of vision with a bifocal. An early presbyope (45years) has (WD)1 ★ The range of clear vision is the distance between the artificial far clear vision through the distance portion from infinity back to 33cm; and and near points while wearing the near vision correction their near portion provides a range from 25cm to 1m away. The second lens is a presbyope in their mid-fifties; due to their reduced accommodation they can only accommodate from infinity back to 67cms and the near portion has a reduced range of 29cm to 50cm – leaving a gap of unclear vision. width with some designs but this case with progressives. However remember that the higher the IP/RP appears to be less of a concern with having two segment dividing lines on ratio dispensed, the closer the patients nowadays. However there the lens can be distracting and gives intermediate working distance will be may still be problems with aberrations, poor cosmesis – particularly in an E- for the patient. Obviously the range for which can be off-putting for patients. type design! Another benefit of having near will be unaffected, as the These do offer better cosmesis the intermediate portion between the reading add remains unchanged. compared with other multifocal lenses distance and near portion is that it and, due to their gradual progression reduces the ‘jump’ experienced by It is also worth noting that dispensing to the near add, they offer a the wearer. Rather than a single opticians are legally allowed to adjust complete range of clear vision. ‘jump’ in bifocal lenses (with the the additions of a prescription to take exception of the E-line ‘no jump’), with account of the patient's working Enhanced readers (degressive lenses) trifocals there are two smaller ‘jumps’ distance. However, it is important to offer very good fields of vision for the instead. make a note that you have done so near and intermediate range (such as on the record card. the Zeiss Business lens), but lack a IP/RP ratio distance correction. OPALs also offer The IP/RP ratio for a trifocal is the ratio Lens availability good fields of vision for near and of the addition of the Intermediate The term trifocal is termed due to the intermediate, but they also provide Portion (IP) to the addition of the presence of three distinct portions of the wearer with a distance zone.