Low vision
From Free net encyclopedia
Template:DiseaseDisorder infobox | }} Low vision is alternatively a general term used to describe lowered visual acuity, and a specific legal term in Canada and the United States used to designate someone with vision of 20/70 or less in the better eye with correction. it is a subspecialty within the professions of optometry and ophthalmology dealing with individuals who have less than (sub)normal vision even with the most accurate conventional prescription available. It can be a result of either congenital or acquired factors. An example of the former is Leber's congenital amaurosis and of the latter age related macular degeneration.
Some people who fall into this category can use their considerable residual vision - their remaining sight - to complete daily tasks without relying on alternative methods. The role of a low vision specialist is to maximize the functional level of a patient's vision by optical or non-optical means. Primarily, this is by use of magnification in the form of telescopic sytems for distance vision and optical or electronic magnification for near tasks.
Some people with significantly reduced acuity may benefit from ‘functional vision assessments’ conducted by individuals trained in the provision of technical aids. Low vision specialists, some of whom are connected to an agency for the blind or to a specific vendor, can provide advice on the best lighting and contrast to maximize remaining vision. These professionals also have access to more unusual vision and non-visual aids, and can instruct patients in their uses.
Visually impaired patients may benefit from high-tech aids such as OCR scanners that can, in conjunction with text-to-speech software, read the contents of books and documents aloud via computer. Vendors also build closed-circuit televisions that electronically magnify paper, and even change its colour contract, for visually impaired users.
The vast majority of patients with low vision can be helped to function at a higher level with the use of low vision devices. Low vision specialists recommend appropriate low vision devices and counsel patients on how better to deal with their reduced vision in general. Many government and private organizations exist to aid the visually impaired.
See also
External links
- National Eye Institute
- Lighthouse International, Helping people with vision loss