The iris is the colored part of the eye. A circular muscle in the iris controls the amount of light entering the eye through the pupil, the black area in the center of the iris.
The lens is located behind the iris and is normally clear. Light passes through the pupil to the lens. Small muscles attached to the lens can change its shape. Tightening or relaxing these muscles causes the lens to change shape, allowing the eyes to focus on near or far objects (accommodation).
| By | Healthwise Staff |
| Primary Medical Reviewer | Kathleen Romito, MD - Family Medicine |
| Specialist Medical Reviewer | Christopher J. Rudnisky - Ophthalmology |
| Last Revised | November 6, 2009 |
© 1995-2011 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.
