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Why diabetes affects the eyes — and what can be done about it

diabetic eye disease

Most people would agree that their eyesight is their most precious sense, and that losing eyesight – even partially – would be a devastating life challenge. People with diabetes – almost 10 percent of the American population – have a higher risk of having eye health problems, which can result in blindness.

If you have diabetes, it’s important to be vigilant and proactive with your eye health, as well as your overall health, to avoid diabetic eye disease.

How diabetes affects the eye

Over time, having high blood glucose levels from diabetes can damage the tiny blood vessels on the retina, causing them to swell and leak liquid into the retina of the eye, a condition call diabetic retinopathy. The retina is the light-sensitive layer of tissue that lines the back of the eye. This damage can cause permanent vision changes, including blurriness and low vision, and sometimes blindness.

Risk factors include:

  • Poorly controlled blood sugar control
  • Unmanaged blood pressure levels
  • Genetics
  • How long you have had diabetes. The longer you've had diabetes, the more likely you are to have retinopathy.) 
  • Smoking


There may be no symptoms in the early stages. As problems become worse, you might experience:

  • Blurry or double vision
  • Flashing lights or missing spots in your vision
  • Dark or floating spots
  • Pain or pressure in one or both eyes
  • Trouble seeing things in peripheral vision

Eye conditions associated with diabetes

Early stage retinopathy (nonproliferative) — capillaries in the back of the eye balloon and form pouches and can move through three stages (mild, moderate, and severe), as more and more blood vessels become blocked.

Almost everyone with type 1 diabetes, and most with type 2, will eventually develop early stage retinopathy.

Advanced retinopathy (proliferative retinopathy) — vessels become so damaged that the retina doesn’t get the oxygen it needs and new blood vessels start to form. These blood vessels are fragile and can break and bleed easily, leading to vision loss.

Detached retina – the result of swollen and weak blood vessels can form scar tissue and pull the retina away from the back of the eye. This results in low vision or blindness if not treated quickly.

Macular edema – swelling in the macula where focus occurs is caused by leaking fluid from the retina’s damaged blood vessels. Macular edema is the most common cause of vision loss for people with diabetes.

Glaucoma – occurs when pressure builds up in the eye. The pressure pinches the blood vessels that carry blood to the retina and optic nerve, which damages them and results in gradual vision loss.

People with diabetes are 40 percent 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.

Cataracts  the eye's clear lens clouds, blocking light. People with diabetes are 60 percent more likely to develop cataracts. People with diabetes also tend to get cataracts at a younger age and have them progress faster.

Can these problems be treated?

Huge strides have been made in the treatment of diabetic retinopathy that can prevent blindness in most people. The sooner it is diagnosed, the more likely these treatments will be successful. The best results occur when sight is still normal.

People with detached retina will have to undergo surgery. For those with retinopathy, several laser treatments can help resolve the situation. 

Eye health tips

How can people with diabetes maintain eye health?

  • Have a primary care provider (PCP). The most important aspect of avoiding diabetic eye disease is early diagnosis and treatment of diabetes. If you have any of the above symptoms, promptly see your PCP. If you need a PCP, see our list of providers.
  • Maintain healthy blood glucose levels.
  • Keep your blood pressure under control.
  • Don’t smoke. Smoking damages the tiny blood vessels in your eyes. Smoking is also linked to an increase in pressure inside your eye that can lead to glaucoma and optic nerve damage.
  • Have annual eye exams, preferably a dilated eye exam. This allows your doctor to examine the backs of your eyes ad check for signs of cataracts, glaucoma, and problems that people with diabetes are more likely to get.

With regular checkups, you can discover problems early and receive treatment to help slow the progression of the disease.

Call 316-689-9989 to inquire about diabetes educational classes at Via Christi.

You can learn more about diabetic eye disease from the American Diabetes Association or National Institutes of Health.

About Patricia Corning RN BSN CDE

Patricia Corning is a diabetes navigator and educator for Via Christi.