What is Diabetic Eye Disease?

Diabetes, a chronic health condition that affects millions of Americans, can have serious consequences on your eyes. Learn how to protect yourself against diabetic retinopathy, when to visit an ophthalmologist, and how diabetic retinopathy is treated.


Sally Wadyka

| Reviewed by

Quinn Wang, MD

Diabetes affects more than 34 million adults in the U.S. People with diabetes suffer from problems with the hormone insulin, which helps the body manage its blood sugar (glucose) levels. There are a few different ways that issues with insulin can result in diabetes: or your body isn’t able to use the insulin properly or you may not produce enough insulin. 

Without proper insulin function, the body’s glucose levels can fluctuate to dangerously high or low levels. This can lead to life-threatening situations such as diabetic coma. 


Having diabetes puts you at higher risk for many other long term health conditions, including eye diseases that can rob you of your vision.

Types of diabetic eye problems

Diabetes can affect the eyes in a variety of ways that increase your risk of eye disease and vision loss. 

For example, chronically high glucose damages the blood vessels in your eyes. Uncontrolled glucose can also speed up the rate at which you develop cataracts. In fact, your risk of cataracts and glaucoma can double when you have diabetes, but age also plays a role in your risk for developing these eye conditions (regardless of whether or not you have diabetes.) 

The most common diabetes-related eye condition is called diabetic retinopathy. This means that there has been damage to the retina, the paper-thin layer of light-sensing tissue that lines the back of the eye. Diabetic retinopathy results from structural damage to the tiny blood vessels — the venules, arterioles, capillaries — in the retina. Uncontrolled high glucose weakens the blood vessel walls, causing them to swell and leak blood and other fluids into the retina. This makes it hard for the retinal cells to get enough oxygen and nutrition. 


There are two types of diabetic retinopathy: nonproliferative (early stages) and proliferative (advanced stages.) 

In nonproliferative diabetic retinopathy, there is a range of damage to the retinal tissue that can come and go. There may also be leakage from the blood vessel walls that leads to swelling of the macula. This condition is called diabetic macular edema. 

In proliferative diabetic retinopathy, the damage to the blood vessels is so severe that the retinal tissues do not get enough oxygen. This “hypoxic” state causes the retina to release signals called vascular endothelial growth factor (VEGF.) VEGF stimulates the growth of brand new blood vessels, a process known as neovascularization. In theory, neovascularization sounds like a good idea, but these new blood vessels are in fact very abnormal: they leak, they break, they bleed, and they tug on parts of the retina, leading to serious consequences such as retinal tears/detachments. 

Vision-threatening consequences of proliferative diabetic retinopathy include:

  • neovascular glaucoma (NVG): A type of angle-closure glaucoma that develops when abnormal blood vessels grow out of the retina and block fluid from draining properly. NVG will result in rapid vision loss if not treated urgently. 
  • Tractional retinal detachment (TRD): This can occur when neovascular scar tissue develops and pulls the retina away from the tissue at the back of the eye. If you notice an increase in floaters (to the point of what seems like you’re seeing a swarm of mosquitoes), flashing lights or a loss of vision, seek medical attention immediately. 

How common is diabetic retinopathy?

People with any type of diabetes—type 1, type 2 or gestational diabetes— can get diabetic retinopathy. One in three diabetics over age 50 have diabetic retinopathy. And the longer you have diabetes, the higher your risk. In fact, it is the leading cause of vision loss among people with diabetes. 

Can diabetic retinopathy be prevented?

Closely monitoring your blood sugar and managing your insulin will help prevent the damage to your eyes that can lead to diabetic retinopathy. Having other health conditions in addition to diabetes —including high cholesterol and high blood pressure—further increases your risk of diabetic retinopathy. Improving and managing those conditions with diet, exercise and medication are important to managing your eye health.


In order to effectively manage diabetes, you have to know that you have it. As many as 20 percent of people with diabetes don’t know they have the disease. Not surprisingly, many people already show signs of diabetic eye diseases before being diagnosed with diabetes. If you are at risk for diabetes, it’s important to have regular medical checkups that include blood sugar tests (e.g. HbA1c.) 


It’s also important to get regular eye exams to detect these problems at their earliest stages. By catching and treating these conditions early, you can minimize vision loss and maintain your eyesight. If you have diabetes, be sure to see your eyecare professional at least once a year for a comprehensive eye exam.

Symptoms of diabetic retinopathy

During the early stages of diabetic retinopathy, you may not notice any vision changes. Or you might have occasionally blurry vision (when your glucose is very high) that resolves after your blood sugar is back under control.


Even during early, nonproliferative diabetic retinopathy, swelling and blood vessel leakage may be bad enough to cause blurry vision and blind spots.


As the condition advances to a later stage (proliferative diabetic retinopathy), new, weak blood vessels start to grow in the vitreous (the gel-like fluid that fills the back of the eye). When these vessels bleed into the vitreous, you may see dark spots or cobweb-like streaks in your vision.


Symptoms of proliferative diabetic retinopathy include:

  • Blurry or fluctuating vision
  • Distorted lines
  • Flashing lights in your field of vision
  • Blind spots or a curtain of black coming down
  • Eye pain
  • Blood in your vision
  • Sudden and severe vision loss

How is diabetic retinopathy diagnosed?

The only way to know for sure if you have diabetic retinopathy is to see your eyecare professional for a comprehensive eye exam. They will use medicated drops to dilate your eyes and examine your retina and other structures in the eyes.


You may also have additional tests to assess any damage to the retina and surrounding blood vessels. Optical coherence tomography (OCT) provides detailed images of the retina and macula. Fluorescein angiography (FA) is an imaging test that uses dye to highlight blood vessel structure and filling patterns so your provider can see if any of them are leaking fluid.


If you have diabetic retinopathy, you may need a comprehensive eye exam as often as every few months. Talk to your eyecare professional about the right schedule to stay on top of any vision changes.

How is diabetic retinopathy treated?

The most effective treatment—especially for early stage retinopathy—is properly controlling your blood sugar. This can not only slow any progression of the disease, but, in some cases, even reverse early vision loss.


For later stage diabetic retinopathy, it’s important to get treatment as soon as possible. There are several therapies that can help prevent your vision from getting worse, including:

  • Injections: Injections of medicines called anti-vascular endothelial growth factor (anti-VEGF) into the eyes can help discourage the growth of new, abnormal blood vessels. These injections can reduce macular edema. Sometimes, intraocular injections of certain steroids can also reduce macular edema. 
  • Laser treatment: Panretinal photocoagulation laser (PRP) is used to destroy damaged retinal tissue. This prevents further release of VEGF. Laser photocoagulation can also seal, shrink and eliminate leaky blood vessels.
  • Surgery: A surgical procedure called vitrectomy removes blood from the vitreous. It can also remove scar tissue from the retina or to repair tractional retinal detachments (TRDs). Vitrectomy is typically used only when there is severe bleeding or retinal damage.

Diabetic retinopathy outcomes

Diabetes, and its related eye conditions, are the leading causes of blindness in the U.S. But vision loss is preventable. If you have diabetes, carefully monitor and control your blood sugar. And see your eyecare provider as recommended for eye exams. When diabetic retinopathy is diagnosed early, treatment can effectively stop vision loss, and sometimes even reverse it.



National Eye Institute

National Institute of Diabetes and Digestive and Kidney Diseases

American Academy of Ophthalmology

American Optometric Association

Merck Manual [Consumer Edition]




Taking good care of your eyes and your overall health can go a long way toward preventing age-related eye conditions. Eating an eye-healthy diet that includes lots of antioxidant-rich fruits and vegetables slows down the formation of cataracts and reduces your risk of macular degeneration. Getting plenty of exercise and maintaining a healthy weight can prevent diseases like diabetes and high blood pressure--both of which affect vision and eye health. And while you may not be able to prevent the presbyopia (and need for reading glasses) that comes with getting older, your eyecare professional can make sure you get the correct vision correction to see clearly.


The sun’s rays contain damaging ultraviolet (UV) light. The same UV rays that burn your skin and lead to skin cancer also affect your eyes. Staring directly into strong sunlight can damage the retina. And repeated sun exposure over time can lead to cataracts, benign growths on the eyes and even eye cancer. Protect your eyes anytime you’re in the sun by wearing sunglasses that block both UVA and UVB rays.


Some people claim that by correcting your vision with prescription glasses or contacts, you’re weakening your eyes—which then leads to worse vision. Their “proof” is that after wearing your corrective prescription for a while, your vision appears blurrier when you’re not wearing it. But that’s likely because you’re now used to seeing the world in clear, crisp detail—and in contrast, your uncorrected vision appears fuzzier. Getting the proper vision correction for your eyes is essential for your eye health. Don’t try to tough it out if you can’t see clearly. Visit your eyecare professional for an in-person or virtual vision screening.


Not having a bright enough light may make it harder to clearly see the words on the page, but it won’t damage your eyes or permanently impact your vision. Because you’re straining to see, you might get a headache or other symptoms of eyestrain. If you want to read in bed without illuminating the entire bedroom, get a reading light that provides just enough brightness to see your book clearly. 


LASIK surgery corrects your distance vision only, so people who are nearsighted benefit most from it. But LASIK doesn’t affect the lens of the eye, the part that helps you focus up close. As you get older, changes to the lens impact your ability to see close up. So even if you have LASIK in your 20s or 30s, you’ll most likely still need reading glasses by the time you hit your 40s or 50s.


Having your face right up next to the bright screen may give you a headache or even cause some temporary eyestrain or fatigue, but it won’t damage your vision. Children are more prone to this behavior than adults—which may be because children can focus close up better than adults can. But if your child can only see the television clearly when sitting close (and has to hold other things close to see them clearly), they may be nearsighted. Taking your child to an eyecare professional for a vision exam will help determine if they need glasses to see clearly.


Most eyecare professionals recommend removing—and thoroughly cleaning—your contacts every night. Even if you use extend-wear lenses that are approved for use a week or month at a time, it’s always safer to give your eyes a nightly break. Your contacts are more likely to accumulate bacteria when you leave them in 24/7, and that can lead to eye infections. Sleeping in your contacts also prevents essential oxygen from getting to your corneas. If you must sleep in your contacts, make it a once-in-a-while event and ask your eyecare provider about contacts that are specially formulated to let more oxygen through. 


Carrots (along with other vegetables like sweet potatoes and dark leafy greens) contain high amounts of beta-carotene, which the body converts to vitamin A. Vitamin A is essential for eye health, and a deficiency of the nutrient is the leading cause of childhood blindness in developing countries. In the U.S., vitamin A deficiency is rare, and few people get so little it could impact their eyesight. Also, there’s no evidence that beta-carotene affects the sharpness of your vision or can prevent near or farsightedness. So while getting lots of beta-carotene in your diet may help keep your eyes healthy, no amount of carrots is going to actually improve your vision and allow you to toss out your glasses or contacts. 


The jury is still out on how effective blue light glasses are for eyestrain. One recent study found they made no difference in eyestrain symptoms during a two-hour-long computer task. But some experts feel they may help alleviate eyestrain and fatigue during prolonged, cumulative screen time. Either way, blue glasses alone won’t solve the problem of too much screen time. The best way to reduce eyestrain is to limit screen time and take frequent breaks when you do need to spend several hours at your computer.


The jury is still out on how effective blue light glasses are for eyestrain. One recent study found they made no difference in eyestrain symptoms during a two-hour-long computer task. But some experts feel they may help alleviate eyestrain and fatigue during prolonged, cumulative screen time. Either way, blue glasses alone won’t solve the problem of too much screen time. The best way to reduce eyestrain is to limit screen time and take frequent breaks when you do need to spend several hours at your computer. 

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