Cataracts
One very common eye issue is cataracts. There are many types of cataracts, but by far the most common are senile cataracts. Cataracts can cause slowly progressive visual loss or blurring, usually over months to years; glare, especially from car headlights; or decreased color perception. As the name suggests, senile cataracts are almost universally found in older individuals.
When we are young, there are 3 basic layers to the lens within the eye. Most centrally lies the nucleus. Surrounding the nucleus, there is a layer called the cortex, and both of these are surrounded by the capsule. The function of the lens is to help focus the light rays onto the retina, which is similar to the lens of a camera focusing images onto film. To perform this function, the cells of the lens are precisely arranged. Any disruption of the cellular pattern will cause a clouding of the lens, which is then called a cataract.
Senile cataracts are due to a number of factors. One of the most important factors is the stress that can be caused by ultraviolet (UV) light damage. UV light damage causes oxidation of many proteins found within the lens cells. Once a certain percentage of oxidized proteins are present, then the cataracts will start to cause symptoms. Some studies have found that high dietary levels of vitamin C, E, and A can slow the progression of cataracts, but please consult your medical doctor before starting dietary supplements of these vitamins. The human lens has protective mechanisms, but these are gradually less effective with increasing age.
Another mechanism contributing to the development of cataracts in older people is the increased density of the nucleus. Throughout life, the lens cells are continually dividing and producing new lens cells. These cells are gradually moved to the center of the lens, the nucleus, where they join all of the other older cells that are also in the nucleus. Therefore, the nucleus not only gets larger as we get older, but it also gets denser because the cells are also compacted together as more cells are produced.
Everyone eventually gets cataracts — but not everybody needs surgery. An ophthalmologist would be able to determine from an eye exam the severity of a cataract and whether an operation is indicated or not. An ophthalmologist would also be able to tell whether or not a cataract is caused by something other than just aging changes, such as previous trauma, an eye tumor, eye inflammation, certain drugs, eye diseases, or systemic diseases like diabetes, Down’s syndrome, or atopic dermatitis.
