|
Retinitis
Pigmentosa is an eye disease in
which the retina slowly has pigment "deposited" on it thus blocking
the light from reaching its receptors. It first affects a person's
night vision and peripheral vision. It is a genetic disorder that is
usually hereditary. Symptoms start with decreased night vision and
later progress to a diminishing of peripheral vision. The rate of
decline varies depending on the genetic makeup of the disorder and
also varies somewhat in individuals, and appears somewhat as
represented in the photo.
Iritis is an
inflamation of the iris (the brown or blue/green colored ring at the
front center of the eye (see eye anatomy photo
by clicking here) behind the clear cornea. It is
a painful condition including redness and light sensitivity. It is
usually rather sudden in onset, and usually recurrent because about
50% of cases having a first attack can expect to get at least one
more attack sometime in their lifetime. To date there is no known
cause.
Color
blindness is the word used to describe mild to
severe difficulties with identifying various colors and shades of
colors. It is a misleading term because colorblind people are not
blind. Rather, they tend to confuse some colors, and a rare few may
not see colors at all. Color blindness comes as a result of a lack
of one or more of the three types of color receptors, red, blue, and
green. Most color perception defects are for red or green or both.
About 4% of males have a color perception defect, but this is rare
in females, less than 1%.
(click here for a short color blind
test...)
| 
