Cataracts are one of the most common causes of correctable vision loss today. Very few patients who live beyond 65 or 70 years old do not develop some form of cataracts. Fortunately, cataract surgery is a modern medical miracle, and vision loss due to cataracts can normally be corrected with this painless, relatively short surgery.
Cataracts are a clouding of the lens in the eye. The lens is that portion of the eye that is responsible for about one-third of the eye’s focusing power. (The cornea, which is the clear outer covering of the eye, is responsible for the other two-thirds of the eye’s focusing power.) The lens lies in the central part of the eye, behind the iris (the colored part of the eye), and all light passing to the back of the eye must first go through the lens. Cataracts begin slowly and often are not noticed at first. The clouding of the lens causes images to appear dull or grayish and for colors to appear washed out. This dull vision occurs because the clouding of the lens causes incoming light to be scattered on the retina. This scattering showers the retina with a blanket of light, thus washing out the visual images that would normally appear in high contrast if properly focused on the back of the eye. The cataract, in effect, lowers the contrast of the visual images making them harder to see, just as a dirty windshield or smudged glasses make it harder to see outside images.
An eye doctor can detect a cataract in your eye by using a device called a slit lamp. The slit lamp allows the doctor to look into your lens and see if there are any clouded spots or a heavy yellowing of the lens. These cloudy areas can start small and then grow over time. The location of the cataract within the lens also greatly impacts patient vision. If the cloudiness is in the central part of the lens, this can have a greater impact than if the clouding is off to one side or another.
Cataracts do not affect everyone’s vision in the same way. Sometimes a patient can see well on a standard E chart because the chart tests using only black-on-white letters, but has trouble in other “real-world” conditions. Since cataracts cause a patient to lose contrast when viewing the external world, it is important in some cases for the patient to be tested with a contrast test or glare test to fully determine the vision loss caused by a cataract. It is not unusual for an elderly patient to pass the driver’s vision test, but yet be unable to see to drive at night. The driver’s vision test requires the patient to read black-on-white letters in a high contrast setting. But when driving at night, images are much lower contrast, and the further contrast reduction caused by the cataracts can greatly depress visual capability under these conditions.
If a cataract is allowed to progress to its full maturity, the lens can become so cloudy that the patient is unable to see from that eye. However, modern cataract surgery can remove the cloudy lens and replace it with an artificial lens, called an IOL (intraocular lens). This surgery allows patients not to suffer the severe vision loss caused by cataracts. In most cases, the patients are able to see better immediately following the surgery. Please visit the ReStor and Toric pages of this site to learn more about the different IOLs we offer. Also, please visit our contact page to schedule an examination with one of our eye care professionals.
Eye Health Partners is proud to offer Birmingham, Nashville, Mobile, Gadsden, Oxford-Anniston, and Montgomery cataracts patients and all those individuals who visit their locations throughout Tennessee and Alabama leading-edge treatments for this debilitating eye disease.