also known as daltonism, is a deficiency in the view of certain colors.
Our retina is made up
of rods and cones, which act as color and light receptors.
Each of the millions of cones are made up of 3 more receptors: red,
green and blue. When functioning correctly, we can see all types of
color; color blindness occurs when there is a problem or lack of
a color receptor in the cones. Red/green color distortion is the
most common type of color vision impairment. In a few very rare cases,
some people can only see in black and white shades.
is almost always an inherited condition although males are
more likely than females to get it. Cones in our eye contain red,
green and blue pigments. When there is damage to one of the cones
or a cone is missing some of the pigment, color blindness occurs.
to distinguish colors (usually red/green and sometimes yellow/blue)
below to the right shows an example of someone who confuses red and
green. To such a person, reds and greens are indistinguishable and
may appear the same.
a person who confuses red and green
color blind people, special contacts can help with color vision. Unfortunately,
there is not a treatment to completely cure color blindness.