Eye Anatomy and Cataracts
Before discussing what a cataract is, you need to know a few basics about how the eye works. The eye sees very much the same as how a camera takes a picture. We look at an object, light rays from that object enter the eye. The light rays are first focused as the rays pass through the cornea. The cornea is the clear tissue in the front of the eye. The iris (blue or brown part of the eye) sits behind the cornea separated by a space filled with fluid. The rays pass through the fluid and through the pupil. The pupil is the opening in the iris.The muscles in the iris relax and contract to change the size of the pupil to aid in focusing just like the iris of a camera. Behind the pupil rests the lens of the eye which is held in place by ligament like structures called zonules. The zonules attach to muscles in the eye which relax and contract to change the lens shape. This lens focuses the rays onto the retina. The retina works like the film of a camera. It takes the light rays and changes them into electrical pulses and transmits them to the optic nerve. The optic nerve then transports the picture to the back of the brain. This portion of the brain contains the image center and is called the occipital lobe.
What is a Cataract?
Many people believe that a cataract is a film that grows over the eye. A cataract is actually a clouding of the lens behind the pupil. Cataracts are the leading cause of vision loss in people over the age of 55.
Causes of Cataracts
Most cataracts develop as an aging process inside the eye. In s small number of cases children can be born with congenital cataracts. Hereditary is responsible for those congenital cataracts but can also play a role in the aging type cataracts.
Risk Factors for Cataracts
There are risk factors that can contribute to developing cataracts at an earlier age.Exposure to ultraviolet light ( UV ) such as sun exposure has been shown to cause cataracts to develop at a younger age. You should always wear sunglasses to minimize its effect. Exposure to X-rays, smoking, and trauma to the eye including other eye surgery can contribute to developing cataract surgery. People who are diabetic develop cataracts sooner than non diabetics. The use of steroids (Cortisone, Prednisone) can cause cataracts.
Final Result of Developing Cataracts
Cataracts are a result of aging and eventually everyone will develop cataracts if they live long enough.