A cataract is a cloudy area in the normally clear lens of the eye. The lens is a tissue located behind the pupil that is responsible for focusing light onto the retina (back of the eye). A cataract usually forms as you get older. As a cataract grows and clouds more of the lens, you may find that performing normal tasks, such as reading and driving, become more difficult. Symptoms of cataracts can include:
- Vision that is cloudy, blurry, foggy or filmy.
- Sudden nearsightedness or sudden improvement in close-up vision.
- Changes in the way you see color, especially yellow.
- Problems driving at night due to the diffusion of streetlights and oncoming headlights
Before surgery, the length of your eye will be measured in what is called an A-scan, and the curve of your cornea will be measured in a technique called keratometry. These measurements help the surgeon to select the proper intraocular lens (IOL) implant for your eye.
The most common procedure used for removing cataracts is called phacoemulsification. An instrument is inserted through a small incision in the side of the cornea (the front part of your eye). High-frequency ultrasound is then used to break up the center of the cloudy lens and suction it out.
After the cloudy lens has been removed, it is replaced with an IOL made of plastic, silicone or acrylic. This new lens allows light to pass through and focus on the retina. The IOLs implanted today usually provide very good vision. There are IOLs that correct astigmatism and there are multi-focal IOLs that correct both near and far vision. After cataract surgery and the implantation of an IOL, you are likely to be less dependent on eyeglasses to see well.
More about cataracts
Cataracts occur when there is a buildup of protein in the lens which makes the lens cloudy. No one knows what causes the buildup of protein, although research indicates that heredity, exposure to ultraviolet (UV) light, diet, smoking, consuming large amounts of alcohol, and exposure to air pollution may be factors.
The most common type of cataract occurs as we age. There are also cataracts that develop in babies (congenital cataracts), cataracts that occur as a result of a disease (diabetes, for example), taking certain medications or exposure to a toxic substance, and cataracts that form after an injury to the eye.
Experts are studying ways to prevent cataracts so that the surgery does not have to be performed.