The Lens:

The lens is located in front of the iris. It is an elastic body, it stretches and returns to its former place. It is biconvex, and almost transparent. Directly in front of the lens is the aqueous, and directly behind it, the vitreous.

The lens is one of the items in a persons body that deteriates with age, like many other body parts. The lens will lose its elasticity, which reduces the ability for it to change shape easily and results in a person needing a type of aid for nearby objects, often in the form of reading glasses.

The purpose of the lens is to refract light that enters the eye through the pupil and gives it the ability to focus on the retina. The lens also contains the ability to absorb ultraviolet radiation and is thus kept from reaching the retina. This absorption of ultraviolet radiation is actually what leads to cataracts--a lack of transparency of the lens--usually found in older people.

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