The eye is a marvelous optical instrument which takes the images from the real-world and focuses them on a tiny spot in the back of the eye. The ability to focus these images comes from two parts of the eye, the lens of the eye and the front cover of the eye, or the cornea. The lens accounts for about 1/3 of the focusing power.
The Natural Lens is Removed During Cataract Surgery
A cataract occurs when the lens of the eye becomes cloudy so that it can no longer focus images. Patients with cataracts see the world as very hazy, because light cannot pass freely through the lens to be focused on the back of the eye. The only way to remove a cataract is to remove the lens itself.
Cataract Surgery Procedure
Cataract surgery is a procedure that removes the cloudy lens from the eye. Today, this procedure can be accomplished very quickly and no stitches are needed. A local anesthetic is used and the surgeon makes a small incision in the outer covering of the eye. Then a technique is used, called phacoemulsification, which removes the lens through the small incision.
At least 95% of the patients receive an artificial lens implant after the cataract is removed. This lens is called an intraocular lens or IOL and is made from the same plastic as certain types of contact lenses. In some cases, a special tiny foldable IOL is used for implantation. This type of lens is inserted into the eye through a very small opening, only 1/8th inch wide. Once in the eye, the lens unfolds to its full size.
The IOL replaces the 1/3 of the eye's focusing power of the natural lens. Without this lens, the eye cannot focus. In a small number of cases, an IOL is not used and the patients must wear glasses or contact lenses to help them see. IOLs are beneficial because they are permanent in the eye. They do not get lost, like glasses, or have to be replaced, like contact lenses. Also, many times the focusing power of the IOL can be determined so that it closely matches your eye. With an IOL, glasses for distance vision may not be needed.This cataract surgery technique has many benefits. No hospital stay is needed, there is no pain, no injections are required, there is quick recovery and the vision after surgery is typically very good.