Monovision and Multifocal Lenses THE GOAL: To provide you good functional vision without glasses at both distance and near most of the time. There are some demanding visual tasks in which monovision or multifocal (bifocal) lenses may not provide acceptable vision and additional glasses may be needed. MONOVISION Monovision interrupts the natural binocular (both eyes together) vision process by using one eye for distance viewing (usually the dominant eye) and the other eye for intermediate and near viewing. This is not how our visual systems were made, but monovision is an accepted modality and has been used for decades. Adapting to having one eye for distance and one for near takes time to adjust to , and is something that is very easy for some and very difficult for others. As the adaptation process proceeds vision becomes clear at all distances, as the brain suppresses the eye that is not being used. Initially you may feel that your distance vision is blurred by your near eye, as your near eye is focused for near and intermediate distances. This perception of distance blur should be reduced over time as the brain learns to suppress the near eye. Noticing a reduction in stereo vision, or depth perception is normal , as the eyes are not working, or teamed together. Noticing a mild reduction in night vision is normal with monovision. Everybody adapts differently , but is good to continue to try monovision for several consecutive days, or longer, to let the adaptation process begin. Monovision is a learned technique, and everybody’s timetable for adaptation is different. Insert your near lens first, and remove it last. During he adaptation process try to not cover or close one eye to see at one distance . If you cover one eye and objects appear clearer, your brain has not yet begin to suppress that eye….try to keep viewing with both eyes together. Initially you may feel that your vision in bright light and in open spaces is better then in dim light, at night or in confined areas. Night driving is often more difficult initially. MULTIFOCALS Bifocal or multifocal lenses are lenses that are made with multiple focal zones and areas to focus light at multiple distances. Technically, these are amazing lenses, but to work well they are dependent on many factors, including prescription, corneal shape, pupil size, quality of tear film and visual demand. As good as multifocal lenses are , there is sometimes some compromise in night vision and vision in low light conditions, when there is not adequate contrast. Some amount of “glare“, “”halo” or a shadow image” is expected with multifocal lenses, but the perception of this can vary between people depending on pupil size and prescription (astigmatism), lighting or contrast. People can often see 20/20, but still notice a slight shadow image or halo around some objects. Multifocals can often provide better computer and intermediate vision then monovision . Often multifocal lenses are fit with different near powers in each eye, the affect of this is to blend focal distances from intermediate to near, and often to provide better distance in one eye by reducing the near power in that eye. The quality of the tear film is important, so keeping the lens surface clean with adequate and proper cleaning is important (if not wearing a one day disposable lens) as well as keeping the lens surface wet and hydrated by using rewetting drops (ex: Blink contacts drops). A clean and hydrated surface will provide the best quality optics and vision . Dry eye can affect vision and visual quality. Be patient and stay motivated, and hopefully we can find an adequate lens to provide you good, quality vision without any additional glasses! If you have any questions or problems please call us. .