| Over three million people in the United
States do not have normal vision even with corrective
lenses. If ordinary eyeglasses do not provide clear vision,
one is said to have low vision. This should not be confused
with blindness. People with low vision still have useful
vision that can often be improved with low-vision devices.
Low vision can result from birth defects, inherited
diseases, injuries, diabetes, glaucoma or macular degeneration.
Although reduced central or reading vision is most common,
a person can have low vision in their side (peripheral)
vision, or a loss of color vision or contrast sensitivity.
Low vision devices or aides are available in optical
and non-optical types. Optical devices use lenses or
combinations of lenses to provide magnification. They
should not be confused with standard eyeglasses. There
are five main kinds of optical devices: magnifying spectacles,
hand magnifiers, stand magnifiers, telescopes and closed-circuit
television. Different devices may be needed for different
purposes. If possible, try the optical device before
purchasing it and be sure you understand how to use
it.
The simplest non-optical technique is to bring the
object of interest closer. Non-optical low vision devices
include large print books, check writing guides, enlarged
phone dials, talking appliances (timers, clocks, computers),
and machines that scan print and read out loud. |
