A cataract results when the natural lens of the eye becomes cloudy. It is usually the result of normal aging. A cataract may also be caused by certain diseases or medications, such as steroids or trauma. A cataract prevents light from being clearly focused, causing blurred vision and problems with glare, such as oncoming car headlights at night. However, a cataract does not form on the eye, but rather within the eye.
Your eyes function similar to the parts of a camera.
Both the camera and your eye have an internal lens that focuses an image onto a film. The retina can be compared to camera film, consisting of a thin layer of photosensitive cells. If the lens of a camera were smudged or dirty, the pictures would turn out unclear. Similarly, as the crystalline lens in your eye becomes cloudy with a cataract, your picture of the world is blurred and discolored.
Cataracts are a natural part of aging. Almost everyone reaching their mid-sixties has some form of a cataract in one or both eyes. Cataracts do not cause irreversible blindness. They are not a growth that covers the surface of the eye, a tumor or a disease, but simply a change in the clarity of your natural lens. Most people who develop cataracts are older, although they may happen for various reasons at any age.
Occasionally, people are born with cataracts, and sometimes a cataract develops in an eye after a significant trauma. Smokers tend to have a higher occurrence of cataracts than non-smokers. Other contributing factors may include family history, previous eye surgery, medications such as a chronic inflammation known as uveitis, corticosteroids, diabetes or even laser vision correction. However, aging seems to be the main cause of cataracts.
Cataracts may take years to form or they may occur rapidly within a few months. And, while cataracts can affect both eyes at the same time, one may progress more rapidly.
In the past the gradual development of a cataract was referred to as “ripening.” Surgeons would wait until a cataract was ripe before removing it, and then it was excised through a large incision in one piece with no lens replacement. Patients gained light perception and could see hand movements only. Eventually, very thick and heavy “cataract glasses” evolved, allowing people to gain a measure of functionality.
Thankfully this is no longer the case. Cataract surgery is now performed whenever a person’s vision is impaired enough to interfere with normal functioning. Modern cataract surgery involves a tiny incision. The lens is then broken apart and it is suctioned gently from the eye and replaced by an artificial lens. Patients now have the option of premium and astigmatism correcting lenses.