What Is Low Vision?
When ordinary eye glasses, contact lenses or intraocular lens implants cannot provide sharp sight, an individual is said to have low vision. This condition should not be confused with blindness. People with low vision still have useful vision which can often be improved with devices. Visual impairment may be mild or severe but in each case visual performance does not meet the individual's needs. Improving vision with visual devices is usually undertaken after your ophthalmologist has completed medical or surgical procedures or determined that such procedures are unwarranted.
What Causes Low Vision?
Though most often experienced by the elderly, people of all ages may be affected. Low vision can occur from birth defects, inherited diseases, injuries, diabetes, glaucoma, cataract and aging. The most common cause is macular degeneration, which is a deterioration of the retina, the light sensitive tissue in the back of the eye. Vision loss from macular degeneration is limited to central vision and fortunately does not cause total blindness since side (peripheral) vision is not affected.
Types of Low Vision
There are different types of low vision and each may require a different kind of treatment option. Types of low vision include reduced reading vision, decreased peripheral vision, loss of color vision, and inability to adjust to light or contrast. Low vision devices can help improve vision; however, there is no single device that will completely restore your vision. There are two general categories of low vision devices which include optical and non-optical.
Optical Low Vision Devices
Optical low vision devices use lenses or combinations of lenses to provide magnification. They should not be confused with standard eye glasses. There are five main kinds of optical devices: magnifying spectacles, hand magnifiers, stand magnifiers, telescopes and closed-circuit TV (CCTV).
Non-Optical Low Vision Devices
Non-optical devices include large-print books, newspapers and magazines, check writing guides, large playing cards, enlarged telephone dials, and high contrast watch faces. Auditory devices, such as machines that talk (timer, clocks, computers) and even machines that scan print and read aloud, are also available.