A blind spot in the visual field, which
may be caused by a variety of disorders
affecting the retina or the optic nerves. A "blind spot" may be one-sided or bilateral and sometimes not appreciated until
a specialist performs full visual field testing.
when certain areas of the retina are insensitive
to color vision. This may be acquired through
damage to the nerve
fibers brought about by optic neuritis---itself caused by a large number of conditions: diseases such as anemia, multiple sclerosis, and diabetes mellitus; abuse of tobacco or alcohol; chemical
toxicity; and vitamin deficiencies.
Treatment of the neuritis is directed toward
the cause, and in some cases recovery is possible if the condition
is not progressive.