Cataracts

A cataract is a clouding of the lens of the eye. People who have diabetes are 60 percent more likely to develop this condition than people who don't. People with diabetes are also more likely to develop cataracts at a younger age, the ADA says. Cataracts in someone with diabetes tend to progress more quickly than in someone without diabetes. Symptoms of a cataract are blurry vision and glare from oncoming headlights at night. If cataracts are severe enough to interfere with vision, they can be treated by surgery.

Glaucoma

Diabetes can lead to glaucoma. Glaucoma is a condition in which the optic nerve is damaged, leading to vision loss. It is caused by a poorly understood group of diseases. Most, but not all, of these diseases cause an increase in intraocular pressure, or pressure inside the eye ball. People with diabetes are about 40 percent more likely to suffer from glaucoma than people without diabetes, according to the ADA. The longer a person has diabetes, the greater the risk for glaucoma. The risk for glaucoma also increases with age. Usually, the damage to the optic nerve that occurs with glaucoma does not cause symptoms. High intraocular pressure can be treated with medicine, usually eye drops, to prevent damage to the optic nerve.

Diabetic Retinopathy

Diabetic retinopathy is damage to the retina, the light sensitive area at the back of the eye. The damage is caused by changes in the blood vessels that supply the cells of the retina with oxygen and nutrition. In the first stage of retinopathy, called background or nonproliferative retinopathy, the blood vessels develop small balloon-like swellings called microaneurysms and leak fluid and blood, or become clogged. When these changes happen to enough of the blood vessels, the cells of the retina are deprived of their blood supply. In response to the lack of blood, new blood vessels grow.

These new blood vessels are abnormal, fragile and leak blood. The result is loss of vision or blindness. This phase is called proliferative retinopathy. Usually, diabetic retinopathy progresses from nonproliferative to proliferative over a period of years. Most often, there are no symptoms of diabetic retinopathy. In some cases mild-to-severe blurring, seeing "strings," "cobwebs" or specks floating in your visual field, or vision loss may be symptoms. Retinopathy can be treated with photocoagulation, laser treatment that stops blood leakage and shrinks blood vessels.

Your retina can be badly damaged before you notice any change in vision, and most people with nonproliferative retinopathy have no symptoms, the ADA says. Even with proliferative retinopathy, people sometimes have no symptoms until it's too late to treat the condition. That's why it's crucial for people with diabetes to see an eye care professional every year for eye examinations.