LOWVISION
Low vision
People with low vision have reduced vision, even when using the best possible corrective lenses. Low vision may be a result of either congenital disease such as retinitis pigmentosa or Leber's congenital amaurosis or of an acquired conditions such as optic atrophy. It is treated within a subspecialty of optometry and ophthalmology called "low vision".The above text is a snippet from Wikipedia: Low vision
and as such is available under the Creative Commons Attribution/Share-Alike License.