Rods, Cones, Night Vision, Averted Vision
Rods and Cones
There are two different kinds of light receptors in the eye.
Rods, which see only black and white, and cones, which
respond to color. The cones are on the central area of the
retina known as the fovea. Rods outnumber cones by about 10:1.
They do not function very well in dim light. In dim light, we
are all blind to color.
Night Vision
When we go from bright lighting conditions to dim lighting
conditions, the rods take over 20 minutes to respond fully.
If we must work with lights on and maintain our night vision,
we can minimize the problem by using red lights or blue lights.
Averted Vision
If you wish to see a very dim object, such as a comet, look a few
degrees to one side of the object and use your peripheral vision
to see the object. In doing this, you are letting the light from
the object reach the rods rather than the less sensitive cones.
This may take a little practice!
For more information, check out the links below.
How Do We See Colors?
Rods and Cones
Color Vision
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