When diabetes goes uncontrolled or isn’t very well-controlled, excess glucose — which is normally broken down by insulin — circulates in the bloodstream. According to the National Diabetes Information Clearinghouse (NDIC), “High blood glucose, also called blood sugar, can damage many parts of the body, such as the heart, blood vessels, eyes, and kidneys.” While the effect on the eye is often dismissed or downplayed in media or diabetes literature, many diabetics sustain permanent eye damage as a result of their disease.
How the eye is damaged with diabetes. As the blood sugar rises, so, too, does blood pressure. High blood pressure raises the pressure in the eyes, and over time, that extra pressure can cause damage. Eyes have a substantial blood supply for their size, and the vessels to the eye are very tiny and delicate. Long before high blood pressure shows noticeable damage to other parts of the body, it can swell these tiny veins and cause them to either rupture or swell shut.
Parts of the eye that are damaged by diabetes. Excessive pressure associated with diabetes can cause damage to the retina, cloud the vitreous fluid due to small levels of bleeding within the eye and affect the lens itself. It is also possible that excessive pressure can change the shape of the eye, morphing it to the point that the lens can no longer focus properly. The optic nerve is also susceptible to damage from the complications of diabetes.
Common eye conditions related to diabetes. The most common eye problem with diabetes is what is referred to as diabetic retinopathy. This is when the blood vessels in the eye swell, rupture, get blocked by swelling or blood clots, or are otherwise damaged. Cataracts and glaucoma are also associated with diabetes and often occur at a much earlier age in diabetics than in individuals who do not have diabetes.