The leading cause of legal blindness in the United States of America is diabetes mellitus. Both of the two most common types of diabetes mellitus, Type I and Type II, can cause vision problems and even blindness. Type I diabetes is typified by the pancreas losing its ability to produce insulin, and Type II diabetes is typified by the body being unable to respond to the insulin the pancreas does produce. Type I diabetes is usually treated with insulin injections, and Type II, by far the more common of the two, does not usually require insulin medications.
Either way, both of these types of diabetes can cause vision problems. The most common vision issue is diabetic retinopathy. In the earliest stages of diabetic retinopathy, structural changes are observed in the capillaries of the eye, thereby impeding the flow of blood to the retina. When the blood cannot flow freely to the retina, then oxygen and nutrients do not make it to the retina where they are needed, causing damage to the retina itself. Diabetes can also alter the clear tissues on the eye, also known as the cornea. This can cause decreased corneal sensations and swelling of the corneal tissue.
Other issues that diabetes can cause that relate to vision are cataracts, retinal swelling, paralysis of the eye muscles, and more. Diabetics are four times more likely to develop cataracts than non diabetics are. The key to preventing the loss of your eyesight due to diabetes complications is careful monitoring. Frequent eye exams are crucial, but so is careful monitoring of your blood sugar to ensure that you keep your diabetes under control. Often, the earliest stages of vision damage go unnoticed until it is too late, so early detection and blood sugar management are key.