Color

Scientists today are not sure how we understand and see color. What we call color depends on the effects of light waves on receptors in the eye's retina. The currently accepted scientific theory is that there are three types of cones in the eye. One of these is sensitive to the short blue light waves; it responds to blue light more than to light of any other color. A second type of cone responds to light from the green part of the spectrum; it is sensitive to medium wavelengths. The third type of light sensitive cone responds to the longer red light waves. If all three types of cone are stimulated equally our brain interprets the light as white. If blue and red wavelengths enter the eye simultaneously we see magenta. Recent scientific research indicates that the brain is capable of comparing the long wavelengths it receives with the shorter wavelengths. The brain interprets electric signals that it receives from the eyes like a computer.

Nearly 1,000 years ago, Alhazen, an Arab scholar recognized that vision is caused by the reflection of light from objects into our eyes. He stated that this reflected light forms optical images in the eyes. Alhazen believed that the colors we see in objects depend on both the light striking these objects and on some property of the objects themselves.