near the optic disk that provides central vision. When the
gaze is fixed on any object, the centre of the macula,
the centre of the lens, and the object are in a straight
line. In the centre of the macula is the cone-containing
fovea. Toward the centre of the macula there are no
blood vessels to interfere with vision; thus, in this area of
the retina, vision in bright light and colour perception
are keenest.
Age-related macular degeneration (ARMD) is a relatively
common condition in people over age 50. There are
two forms of ARMD, known as wet and dry. In wet ARMD
new blood vessels form beneath the retina that are very
fragile and prone to breakage and bleeding, thereby compromising
central vision acuity. As a result, wet ARMD
advances more quickly and is more severe than dry
ARMD, which is characterized by the presence of drusen
(tiny yellow deposits on the retina) and the loss of retinal
pigment and may progress so slowly that it goes unnoticed.
Both conditions reduce central vision but do not
interfere with peripheral vision
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