Diabetes is a disease that affects the body's ability to produce or use insulin effectively to control blood sugar (glucose) levels. Although glucose is an important source of energy for the body's cells, too much glucose in the blood for a long time can cause damage in many parts of the body, including the heart, kidneys, blood vessels and the small blood vessels in the eyes.

When the blood vessels in the eye's retina (the light-sensitive tissue lining the back of the eye) swell, leak, or close off completely — or if abnormal new blood vessels grow on the surface of the retina — it is called diabetic retinopathy.

People who are at greater risk of developing diabetic retinopathy are those who have diabetes or poor blood sugar control, women who are pregnant, and people with high blood pressure, high blood lipids or both. Also, people who are from certain ethnic groups, such as African-Americans, Hispanics, and Native Americans, are more likely to develop diabetic retinopathy. In fact, a new study confirms that diabetes is a top risk factor for vision loss among Hispanics.

Something to remember: diabetes can cause vision in your eyes to change even if you do not have retinopathy. If your blood sugar levels change quickly, it can affect the shape of your eye's lens, causing blurry vision, which goes back to normal after your blood sugar stabilizes.

Did you know there is also a link between diabetes and cataracts? Permanent blurring of vision due to cataracts can also result from changes to the lens due to excess blood sugar. Cataract surgery may be necessary to remove lenses that are clouded by the effects of diabetes and replace them with clear intraocular lenses (IOLs) to restore clear vision. Maintaining good control of your blood sugar helps reduce episodes of temporary blurred vision and prevent the permanent clouding of the lens that would require surgery to correct.

Learn more about diabetic retinopathy and how to save your sight.