There are a number of recognized vision problems, caused by a number of different things. The most common conditions are usually due to a misshapen eyeball or aging eyes, and they are often easily corrected. Astigmatism, myopia, hyperopia, presbyopia, glaucoma, and cataracts are some of the more common vision problems.
An astigmatism is one of the most common vision problems, and some ophthalmologists estimate that just about everyone has an astigmatism to some extent. This eye disorder is characterized by an irregularly shaped cornea. Because of this, the light that passes through the cornea does not hit the retina correctly. Instead of focusing on it directly, as it should, rays of light focus on a few different spots, causing certain parts of an image to be out of focus.
Myopia is another of the more common vision problems, and is usually referred to as nearsightedness. When a person's eyeball shape is longer than it should be, rays of light that go through the cornea focus slightly in front of the retina. This condition makes objects and images that are far away appear blurry, while objects that are close up, such as words in a book, are clearer.
Hyperopia, or farsightedness, is basically the opposite. The eyeball is shorter than it should be, and rays of light focus just behind the retina. This often causes objects that are close up to appear blurry or out of focus, while far away objects are clear. This condition usually presents itself during childhood, but many people's eyes compensate for the problem, and usually, no treatment is necessary at a young age.
As people get older, though, hyperopia often develops into a problem referred to as presbyopia. Later in life, a person's eye becomes less able to compensate for hyperopia. The farsightedness that these people experience as a child could come back again.
Glaucoma is one of the most common vision problems people deal with as they age. When this eye problem occurs, the pressure of the fluid inside the eyeball begins to build up. Symptoms of this disorder include seeing halos around lights and tunnel vision. This increasing pressure can cause damage to the optic nerve, which relays messages to the brain. If this condition is not treated, it could result in partial or complete blindness.
Another eye disorder common in older people is a cataract. A cataract is a foggy or cloudy area that has developed on the natural lens of the eyeball. This area can block the rays of light that enter the eye and cause a number of vision problems, including blurry or cloudy vision, and sensitivity to light.
Almost all vision problems can be diagnosed after a thorough eye exam performed by an ophthalmologist. Treatment for astigmatism, myopia, hyperopia, and presbyopia usually includes some type of corrective lenses like eyeglasses or contacts. There has also been some success with certain types of surgery, such as laser surgery.
Mild cases of glaucoma can be treated with eye drops to relieve the intraocular pressure, but some patients may need surgery to correct the problem. Some cataracts may require no treatment at all, but if it is interfering with a patient's daily life, surgery may be recommended. During cataract surgery, the patient's natural lens is removed and replaced with a synthetic one.