The structures of the eye that allow light to enter are normally clear and transparent, such as the cornea and lens. This ensures that the light can completely reach the retina and form a visual picture. However, as people age, the lens material becomes stiff and thick. The proteins in the lens start to change color and clump together. This produces a cloudiness or opacity in the lens which is referred to as a cataract. Read more about cataracts here.
A cataract is a cloudiness that forms in the lens of the eye. Normally, the lens is clear to allow light to enter into the eye structures for the retina to form a visual image. When proteins in the lens clump together, they can become less clear and hence form a cloudy spot called a cataract. This spot causes some of the light entering the eye to scatter and blocks some of this light, resulting in blurry vision.
Macular degeneration is a disease that affects the center of the visual field. Central vision is needed for activities like reading, driving, and recognizing people. When looking directly at a person, central vision allows you to be able to see a person’s face and recognize them. In the same way, when watching television, you use your central vision to be able to enjoy the show.
Glaucoma is often called the “silent thief of sight,” as it is often a painless, symptom-less disease that gradually takes away vision permanently. It affects about three million Americans and only half of those affected even know that they have the disease!
Glaucoma is a disease that progressively damages the optic nerve. The optic nerve is of critical importance to vision because it transmits all signals from the retina to the brain. Without a functioning optic nerve, a person cannot see anything and is blind.
Inside the front part of the eye is a fluid filled space called the anterior chamber. This “chamber” is filled with a fluid called Aqueous Humor, which is constantly being freshly made and drained in order to provide nutrition and oxygen to the front part of the eye. An imbalance of this fluid’s production and drainage can lead to high pressure within the eye, which in many cases of glaucoma can lead to nerve damage. Of note, this eye pressure is unrelated to the body’s blood pressure and the eye pressure can be normal even if the blood pressure is high (and vice versa).