Aniridia is a visual disorder that involves various parts of the eye although the word aniridia is a term by itself referring to “eyes that lack the iris”. The disorder is congenital, and it is passed on from parents to a child which makes it hereditary. Aniridia results when there is incomplete development of the iris and normally affects both eyes.
The iris, a colored ring surrounding the pupil, plays a significant role in vision. Depending on the intensity of light in the environment, the iris opens or closes, expands or contracts, enabling it to play its vital function of regulating the amount of light that must pass through the ocular globe to reach the retina. The big black central pupil and in some cases a small colored strip are the external appearances of the eye that are most affected by the visual disorder.