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How Diabetes Causes Blindness


Diabetes damages small blood vessels throughout the body. Diabetic retinopathy happens when prolonged high blood sugar damages the blood vessels of the retina. This is the part of the eye that sends images to your brain. Other conditions that increase your risk include high blood pressure, high cholesterol, and kidney disease.

Diabetic retinopathy can lead to poor vision and even blindness. It often gets worse over many years.

At first, the blood vessels in the eye get weak. Blood and other liquid can leak into the retina from the blood vessels. If the fluid leaks into the center of your eye, you may have blurry vision.

If blood sugar levels stay high, the condition will keep getting worse. New blood vessels grow on the retina. These blood vessels can break open easily. If they break open, blood can leak into your eye and change your vision. This bleeding can also cause the retina to move away from the wall of the eye (retinal detachment). Sometimes people don't have symptoms until it's too late to treat them. That's why regular eye exams are important.

Retinopathy can also cause swelling in the middle of the retina (macula). This is called macular edema.

Treatment for diabetic retinopathy

There's no cure for diabetic retinopathy. But treatment often works very well to prevent, delay, or reduce vision loss. The earlier retinopathy is found, the easier it is to treat. And it's more likely that vision will be saved.

Treatment options include:

Laser treatment (photocoagulation).

This usually works very well to prevent vision loss if it's done before the retina has been severely damaged.

Anti-VEGF (vascular endothelial growth factor) or an anti-inflammatory medicine.

Sometimes injections of these types of medicine can help to shrink new blood vessels when diabetic retinopathy is advanced.

Surgical removal of the vitreous gel (vitrectomy).

This may help improve vision if the retina hasn't been severely damaged.

Keeping your blood sugar levels within your target range can help keep eye problems from getting worse.

Many people with retinopathy need to be treated more than once as the condition gets worse.

Major causes of blindness from diabetes

This table shows the major causes of blindness in people who have diabetes and what you can do to help prevent vision loss.

Keeping your blood sugar levels and blood pressure within a target range is always important. You also need regular dilated eye exams to help find eye diseases early. Finding and treating eye diseases early can help prevent or delay vision loss.

Major causes of blindness associated with diabetes


How it causes vision loss

How to help prevent it

Diabetic retinopathy

It damages the retina, the section of your eye that captures visual information.

  • Keep blood sugar levels in a target range.
  • Control blood pressure.
  • Get regular eye exams.
  • Treat retinopathy early to keep the disease from progressing.


It increases pressure in the eye, which damages your retina.

  • Get regular eye exams to check for the disease.


It clouds the lens, the section of your eye that focuses light.

  • Protect your eyes from ionizing radiation (X-rays) and UV radiation (sunlight).
  • Keep blood sugar levels in a target range.


Current as of: October 2, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.