You may have heard that diabetes causes eye problems and may lead to blindness. People with diabetes do have a higher risk of blindness than people without diabetes.

But most people who have diabetes have nothing more than minor eye disorders. You can keep minor problems minor. And if you do develop a major problem, there are treatments that often work well if you begin them right away.

Eyesight Insight for Diabetics
To understand what happens in eye disorders, it helps to understand how the eye works. The eye is a ball covered with a tough outer membrane. The covering in front is clear and curved. This curved area is the cornea, which focuses light while protecting the eye.

After light passes through the cornea, it travels through a space called the anterior chamber (which is filled with a protective fluid called the aqueous humor), through the pupil (which is a hole in the iris, the colored part of the eye), and then through a lens that performs more focusing. Finally, light passes through another fluid-filled chamber in the center of the eye (the vitreous) and strikes the back of the eye, the retina.

Like the film in a camera, the retina records the images focused on it. But unlike film, the retina also converts those images into electrical signals, which the brain receives and decodes.

One part of the retina is specialized for seeing fine detail. This tiny area of extra-sharp vision is called the macula.

Blood vessels in and behind the retina nourish the macula. The smallest of these blood vessels are the capillaries.

Glaucoma and Diabetes
People with diabetes are 40% more likely to suffer from glaucoma than people without diabetes. The longer someone has had diabetes, the more common glaucoma is. Risk also increases with age.

Glaucoma occurs when pressure builds up in the eye. In most cases, the pressure causes drainage of the aqueous humor to slow down so that it builds up in the anterior chamber. The pressure pinches the blood vessels that carry blood to the retina and optic nerve. Vision is gradually lost because the retina and nerve are damaged.

There are several treatments for glaucoma. Some use drugs to reduce pressure in the eye, while others involve surgery.