Cataracts are unfortunately a fact of life for all of us. As we get older we will all get them but what causes cataracts? The National Eye Institute has taken the time to put together some great information about cataracts as well as many other eye issues.
What are cataracts?
A cataract is a clouding of the lens in the eye that affects your vision. Most cataracts are related to aging and are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery. A cataract can occur in either or both eyes. It cannot spread from one eye to the other.
What is the lens?
The lens is a clear part of the eye that helps to focus light, or an image, on the retina. The retina is the light-sensitive tissue at the back of the eye. In a normal eye, light passes through the transparent lens to the retina. Once it reaches the retina, light is changed into nerve signals that are sent to the brain. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.
What causes cataracts?
The lens lies behind the iris and the pupil. It works much like a camera lens, focusing light onto the retina at the back of the eye, where an image is recorded. The lens also adjusts the eye’s focus, letting us see things clearly both up close and far away. The lens is made of mostly water and protein and this protein is arranged in a precise way that keeps the lens clear and letting light pass through it. As we age however, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see. Researchers suspect that there are several causes of cataract, such as smoking and diabetes. Or, it may be that the protein in the lens just changes from the wear and tear it takes over the years.
How do cataracts affect vision?
Age-related cataracts can affect your vision in two ways:
Clumps of protein reduce the sharpness of the image reaching the retina. The lens consists mostly of water and protein. When the protein clumps up, it clouds the lens and reduces the light that reaches the retina. The clouding may become severe enough to cause blurred vision. Most age-related cataracts develop from protein clumpings. When a cataract is small, the cloudiness affects only a small part of the lens. You may not notice any changes in your vision. Cataracts tend to “grow” slowly, so vision gets worse gradually. Over time, the cloudy area in the lens may get larger, and the cataract may increase in size. Seeing may become more difficult. Your vision may get duller or blurrier.
The clear lens slowly changes to a yellowish/brownish color, adding a brownish tint to vision. As the clear lens slowly colors with age, your vision gradually may acquire a brownish shade. At first, the amount of tinting may be small and may not cause a vision problem. Over time, increased tinting may make it more difficult to read and perform other routine activities. This gradual change in the amount of tinting does not affect the sharpness of the image transmitted to the retina. If you have advanced lens discoloration, you may not be able to identify blues and purples. You may be wearing what you believe to be a pair of black socks, only to find out from friends that you are wearing purple socks.
When are you most likely to have a cataract?
The term “age-related” is a little misleading. You don’t have to be a senior citizen to get this type of cataract. In fact, people can have an age-related cataract in their 40s and 50s. But during middle age, most cataracts are small and do not affect vision. It is after age 60 that most cataracts cause problems with a person’s vision.
At Schmidt’s Optical and Hearing™ in Stuart Florida our well trained employees will be happy to help you with any questions or needs you may have before and after you have cataracts. Stop in and see us today.