Cataract is a word used to describe the loss of transparency, or clouding, of the normally clear lens of the eye. As one ages, chemical and physical changes occur in the lens that make it less transparent.

The loss of transparency may be so mild vision is hardly affected or so severe that no shapes or movements are seen, only light and dark. When the lens gets cloudy enough to obstruct vision to any significant degree, it is called a cataractous lens or "a cataract."

Changing glasses or contact lenses may temporarily sharpen your vision if a cataract is present, but surgery will eventually be required. The most common cause of cataract is aging. Other causes include trauma, medications such as steroids, systemic diseases such as diabetes. Occasionally, babies are born with a cloudy lens or cataract.

Reducing the amount of ultraviolet light exposure by wearing a wide-brim hat and sunglasses may reduce your risk for developing a cataract but once developed there is no cure except to have the cataract surgically removed. Outpatient surgical procedures can remove the cataract through a small incision. The time to have the surgical procedure is when your vision is bad enough that it interferes with your lifestyle.

Cataract surgery is a very successful operation. One and a half million people have this procedure every year and most have a successful result. As with any surgical procedure, complications can occur during or after surgery and some are severe enough to limit vision. But in most cases, vision, as well as quality of life, improves.

Cataract Symptoms
Your eye works a lot like a camera. Light rays focus through your lens on the retina, a layer of light sensitive cells at the back of the eye. Similar to film, the retina allows the image to be "seen" by the brain. But over time the lens can become cloudy and prevent light rays from passing clearly through the lens. This cloudy lens is called a cataract.

The typical symptom of cataract formation is a slow, progressive, and painless decrease in vision. Other changes include: blurring of vision; glare, particularly at night; frequent eyeglass prescription change; a decrease in color intensity; a yellowing of images; and in rare cases, double vision.

Ironically as the lens gets harder, farsighted or hyperopic people may experience improved distance vision and be less dependent on glasses. However, nearsighted or myopic people become more nearsighted or myopic, causing distance vision to be worse.

Some types of cataracts affect distance vision more than reading vision. Others affect reading vision more than distance vision.

Intra ocular Lenses (IOLs)
An Intra ocular lens (IOL) is a tiny, lightweight, clear plastic disk placed in the eye during cataract surgery. An IOL replaces the focusing power of the eye's natural lens.

The lens of the eye plays an important role in focusing images on the retina. If the lens loses its clarity, as it does when a cataract develops, light rays do not focus clearly and the image one sees is blurry.

The only treatment for a cataract is to remove the cataratous lens and usually replace it with an IOL. Intra ocular lenses have many advantages. Unlike contact lenses, which must be removed, cleaned, and reinserted, the IOL remains in the eye after surgery.

An IOL may be placed either in front of or behind the iris. Behind the iris is the most frequent placement site. They can be hard plastic, soft plastic or soft silicone. Soft, foldable lenses can be inserted through a small incision which shortens recovery time following surgery.

The rapid evolution of IOL designs, materials, and implant techniques have made them a safe and practical way to restore normal vision after cataract surgery.

Phacoemulsification (Phaco)
Phacoemulsification is a surgical method used to remove a cataract, which is a clouding of the eye's naturally clear lens. A cloudy lens interferes with light passing through to the retina, the light-sensing layer of cells at the back of the eye. Having a cataract can be compared to looking at the world through a foggy window.

In phacoemulsification, an ultrasonic oscillating probe is inserted into the eye. The probe breaks up the center of the lens. The fragments are suctioned from the eye at the same time. A small incision that often does not require sutures to close can be used since the cataract is removed in tiny pieces.

The clear capsule which surrounds the cataract is left in the eye as a platform for the intra ocular lens, or IOL, which is placed permanently inside to help focus light onto the retina. Vision returns quickly and one can resume normal activities within a short period of time.

Posterior Capsulotomy
A posterior capsulotomy is a surgical laser procedure that may be necessary after cataract surgery.

During cataract surgery part of the front (anterior) capsule that holds the lens is removed. The clear back (posterior) capsule remains intact. As long as that capsule stays clear one has good vision. But in a varying percentage of people, the posterior capsule loses its clarity. When this happens, an opening can be made in the capsule with a laser (posterior capsulotomy) to restore normal vision.

Before the laser procedure, the ophthalmologist does a thorough ophthalmic examination to make sure there is no other reason for vision loss.

A posterior capsulotomy is painless and takes just a few minutes. Vision should improve within hours.