What is the main anatomical structure affected by color deficiency?

The main anatomical structure affected by color deficiency is the retina. The retina contains specialized cells known as photoreceptors, specifically cones, that are responsible for color vision. There are three types of cones—red, green, and blue—that respond to different wavelengths of light. A deficiency or absence of one or more types of these cones leads to various forms of color vision deficiencies, commonly known as color blindness.

In contrast, other structures like the iris, cornea, and lens are involved in different functions related to vision, such as regulating light entry, focusing light, and protecting the inner eye structures, but they do not directly contribute to the perception of color. Therefore, any impairment in color vision is specifically linked to changes or deficiencies within the retinal photoreceptors.