At birth and immediately after, the infant vision is quite different than that of an adult. Notably, the color vision ability of a baby is limited to only black, white, and grayscale colors. While this will change rapidly as the child develops, in the first weeks and months of life, the color perception is very limited. The part of the eye responsible for seeing and perceiving colors is the cone photoreceptors in the retina. These cone photoreceptors are not born fully developed and take months to develop into the adult form which is capable of normal color detection.
In the retina, there are two types of photoreceptors which contribute to vision. There are rod photoreceptors and cone photoreceptors. Rod photoreceptors are used for seeing in dim lighting, observing motion, peripheral vision, and seeing in black and white. Cone photoreceptors are used for seeing in bright lighting, fine detail, central vision, and color vision. The shape and function of the two types of photoreceptors are similar but different enough to allow the near opposite functions in the retina. Both types of photoreceptors connect with the optic nerve and travel into the brain to send signals which are perceived as vision.
While cone photoreceptors can be identified in fetal eyes, these are not yet functional photoreceptors. After birth and exposure to light, the cones will begin to develop and migrate to the center of the vision. Usually, within the first six months of life, there are enough cone photoreceptors present to have near adult levels of visual perception and color vision. The first functional cone photoreceptors will begin to send signals at only a few months old and will rapidly progress to adult numbers of photoreceptors by eight months old.
Since cone photoreceptors are solely responsible for color vision, the infant will not begin to see color until these photoreceptors are developed and functional at a few months old. Before this, the rod photoreceptors will allow only black, white, and gray color perception. While black and white, the infant is still able to detect different hues and saturation levels as well as contrast between two colors. As the cone photoreceptors develop, the cones which are responsible for seeing and signalling for red hues will develop first, allowing the infant to see red in addition to the black and white hues. Then the cone photoreceptors which perceive green will develop and the color vision will begin to take shape as red, yellow, orange, and green hues are distinguishable. The final cone photoreceptors to develop are blue photoreceptors and complete the color vision palette with blue, indigo, and violet hues. All of these cone photoreceptors are developed and functional around six months of age.
If an individual is color blind, it is likely that the genetic mutation led to an abnormality or absence of either the red or green cone photoreceptors. In these cases, the color vision development may be slower than normal color vision individuals and may take a few more months to reach the final adult levels of perception. Not all color blind cases will cause color vision development to delay but it is likely that there is some degree of difference when there is a measurable color vision deficit.
Our eye doctor at The Optical Centre in Longmont, CO excels in the prescription of glasses, contact lenses and the diagnosis of a variety of eye diseases. Call our optometrist at 303-772-6650 or schedule an eye exam appointment online if you would like to learn more about infant vision. Our eye doctor, Dr. Erica Whitmire provides the highest quality optometry services and eye exams in Longmont, Colorado and its surrounding areas.