
The eye is the organ used to see. It's sphere-shaped, hollow and filled with fluid.
The outer layer (sclera, or white, and cornea) is used for protection made of fibers.
The middle tunic layer (choroid, ciliary body and the iris) is made of many small blood vessels.
The innermost layer (the retina) is made of many nerves that sense light.
The fluids in the eye are divided by the lens into vitreous, which is behind the lens and the aqueous, which is in front of the lens.
The lens itself is flexible and held in place by ligaments that allow it to change shape to focus light on the retina, which is composed of sensory neurons.
Information provided by: MedlinePlus Medical Encyclopedia


A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M's editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2008, A.D.A.M., Inc.