ClearView Logo
Home   •    Glossary

Iris


The iris is the colored part of the eye, located between the cornea and the lens. It controls the size of the pupil and, consequently, the amount of light that enters the eye. The iris is made up of muscles that contract or dilate to adjust the size of the pupil in response to changing light conditions. In bright light, the iris contracts to make the pupil smaller, reducing the amount of light that enters the eye. In dim light, the iris dilates to allow more light in, improving vision. The color of the iris is determined by the amount of melanin pigment, and it can range from blue, green, or brown to hazel or gray.

  • Causes: The development of the iris and its pigmentation is largely genetic, determined by the amount of melanin present. People with more melanin have darker irises, while those with less melanin have lighter-colored eyes. Some medical conditions or injuries can cause abnormalities in the iris, such as aniridia (absence of the iris) or coloboma (a defect in the iris).
  • Symptoms: Problems with the iris, such as damage or disease, can lead to issues with pupil function and light regulation. For example, trauma to the iris can cause it to lose its ability to properly control the pupil, leading to sensitivity to light (photophobia) or difficulty seeing in different lighting conditions.
  • Treatment: Issues related to the iris, such as abnormalities in its structure or function, may require medical or surgical treatment. For example, iris reconstruction surgery can help repair damage from trauma or disease. People with light sensitivity may benefit from tinted lenses or prescription sunglasses to help regulate light entering the eye.

GET STARTED WITH CLEARVIEW

Schedule your free consultation with Dr. Sandy T. Feldman to discover how achieving visual freedom can change your life.

Google Logo
Facebook logo large
Facebook Logo
Yelp Logo