How can diabetes affect my eyes?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

High blood glucose and high blood pressure (BP) from diabetes can hurt four parts of your eye:

  • Retina: The retina is the lining at the back of the eye. The retina's job is to sense light coming into the eye.
  • Vitreous: The vitreous is a jellylike fluid that fills the back of the eye.
  • Lens: The lens is at the front of the eye and focuses light on the retina.
  • Optic nerve: The optic nerve is the eye's main nerve to the brain.

This answer is based on source information from the National Diabetes Information Clearinghouse (NDIC).

Dr. Manvi P. Maker
Ophthalmologist (Eye Specialist)

If the blood sugars fluctuate significantly or are consistently high, then that is a danger to your eye health and vision. If your sugars are stable and within the target range, your chance of severe vision loss from the diabetes is significantly decreased. However, diabetes does cause some damage to the back of the eye. How significant those changes are and how they impact your vision depend on what the blood sugar control has been to that point.


Diabetes is the number one cause of new cases of blindness in people between the ages of 20 and 74. And having diabetes increases your risk of developing cataracts, glaucoma, and diabetic retinopathy. These conditions can be treated, but they may not cause any symptoms until irreversible damage has been done, so make sure to get your eyes checked at least once a year. You can also protect your vision by keeping your blood sugar levels as close to normal as possible.

Diabetes increases the chance of experiencing an eye disorder, although many such disorders are minor. But diabetes is the leading cause of blindness in people ages 20 to 74, and thus should not be taken lightly. People with diabetes should have regular eye exams in order to identify and treat problems as they arise.

High blood sugar causes the lens of the eye to swell, resulting in blurred vision. Returning to a target blood sugar range should eventually improve this condition. Ongoing blurred vision might indicate one of three eye complications that are common to diabetics: retinopathy, cataracts, and glaucoma.

Retinopathy, caused by changes in the blood vessels of the retina, is the most common diabetic eye disease. In one stage of retinopathy, capillaries in the eye swell and develop pouches, which can lead to blurred vision. At a more advanced stage, blood vessel damage leads to scar tissue and the growth of weaker, leaking blood vessels. Sometimes there are no symptoms of this retinal damage, which is just another reason to stay on top of regular eye exams.

Blurred or glared vision might be a sign of a cataract, a clouding of the lens of the eye. Diabetics are 60 percent more likely than non-diabetics to develop the condition, more likely to develop it at an early age, and more likely to have the condition progress rapidly. Wearing glare‐control glasses and sunglasses might help with mild cataracts; more developed cataracts are usually surgically removed.

Heightened pressure in the eye can cause glaucoma, which results in inadequate drainage of liquid in the eye, damage to nerves and blood vessels, and limited blood flow to the retina and the optic nerve. Glaucoma might not be accompanied by early symptoms. It is often treated with eye drops, laser surgery, or other forms of surgery.

Recommendations to protect your eyes:

  • Good UV blocking sunglasses
  • 1,000mg vitamin C and 1,000 mg MSM daily
  • Consider L‐carnosine eye drops 2‐3 times daily.
Dr. Douglas S. Denham, DO
Family Practitioner

Yes, diabetes can cause several problems with vision. Patients with very high blood sugars may experience blurry vision due to changes in the lens of the eye caused by high blood sugar. This is often a presenting sign of diabetes. For these patients, we generally do not recommend vision prescription adjustments because once their blood sugars start getting under control, their vision will return to normal.

For people who have poorly controlled blood sugars for longer periods of time, years, vision changes can occur for another reason. This is called diabetic retinopathy. It is the result of new blood vessels that grow on the retina. These blood vessels can then rupture causing bleeding which results in vision changes. This is why it is important for diabetics to have annual visits to the ophthalmologist or optometrist. Regular eye exams and prompt referral to a retina specialist are important in these cases to preserve vision.

If you have diabetes, your eyes are at special risk. The leading cause of blindness in adults under 65 is diabetic retinopathy, in which small blood vessels in the eyes weaken and burst. The condition affects nearly everyone with type 1 diabetes and 60% of those with type 2 within 20 years of diagnosis.

You're also more likely to develop cataracts and glaucoma, a condition in which pressure builds in the eye, eventually destroying the optic nerve and leading to vision loss.

The good news? Early diagnosis and effective blood-sugar and blood-pressure control can prevent blindness in about 90% of cases of diabetic retinopathy. As someone with diabetes, it's best to get those screenings from a qualified ophthalmologist. You should be screened immediately upon diagnosis and at least every year thereafter.

Stacy Wiegman, PharmD
Pharmacy Specialist


Diabetes can damage the retinas of your eyes. High blood sugar levels and high blood pressure can cause the tiny blood vessels of your retinas to swell, weaken and possibly clog. Over time, blood vessels may break and leak blood into the vitreous (the gel-like fluid within the eye), also blocking light from reaching your retinas. This can cause blurry vision, flashing lights or blank spots, floating spots or darkness. The damaged blood vessels can also form scar tissue, which could pull the retina away from the back of the eye. This could lead to retinal detachment and partial or total blindness that may be permanent if you don't seek immediate medical care. Keeping your blood glucose and your blood pressure within a normal range are important ways to protect your eyes from retinal damage from diabetes. Also follow your doctor's recommendations for regular eye examinations to monitor the health of your eyes.

William Lee Dubois

Diabetes-related damage to the retina is called retinopathy, and it can lead to blindness. High blood sugar is the leading cause of eye trouble for people with diabetes, but even if your blood sugar is perfect, you need to have your eyes checked every year. If trouble is detected early, there is much that can be done. But not if you wait until you're blind.

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Mr. Eliot LeBow, CDE, LCSW

Blurred vision: When blood sugar levels are too high, fluid will be extracted from all tissues in the diabetic’s body, including the lenses of ones eyes. Affecting the ability to focus clearly.

Long Term: The blood vessels in the retina can be damaged called diabetic retinopathy, untreated will lead to blindness. There are higher risks for problems, such as glaucoma and cataracts.

Diabetes can cause several eye problems. Diabetes is a leading cause of blindness. Fortunately, many eye problems are treatable if they are identified early. One of the most serious eye problems caused by diabetes is retinopathy. In this disease, fragile blood vessels grow in the back of the eye and can bleed easily. Such bleeding can cloud the vision and lead to permanent scarring of the back of the eye (the retina).

People with diabetes can also develop cataracts (a permanent clouding of the lens), "floaters" that temporarily interfere with vision, and a swelling of the eye nerves that can cause permanent damage to your sight (macular edema). Abnormal function of the nerves that control the eye muscles can result in double vision.

All people who develop double vision should see an eye doctor as soon as possible to rule out other possible causes, such as a small stroke. Cataracts can be corrected surgically. Laser therapy helps stop retinopathy or macular edema if it is performed before there is too much damage. A yearly eye examination by a doctor who specializes in diabetic eye disease is the best way to detect eye problems in the early stages, and keeping your blood glucose near normal can help reduce your risk of eye disease.

Many older adults have diabetes, a disease in which the body does not use or store sugar properly.

Diabetes can cause changes in the veins and arteries that carry blood throughout your body. This disease can affect your vision by causing cataracts, glaucoma and, most important, damage to blood vessels inside the eye.

When blood vessels in the retina are damaged, they may leak fluid or blood and grow fragile, brush-like branches and scar tissue. This condition, called diabetic retinopathy, can blur or distort the images that the retina sends to the brain.

Retinopathy progression can be slowed through good control of blood sugar and blood pressure. When retinopathy does develop, laser surgery is the most common treatment. It often does not return vision to normal but is very helpful in preventing continued loss of vision. Injection of medication and other types of surgery may also be needed.

You can get cataracts and glaucoma if you have diabetes. People without diabetes can get these eye problems, too. But people with diabetes get these problems more often and at a younger age.

  • A cataract is a cloud over the lens of your eye-the lens is usually clear and focuses light onto the retina. A cataract makes everything you look at seem cloudy. You need surgery to remove the cataract. During surgery your lens is taken out and a plastic lens, like a contact lens, is put in. The plastic lens stays in your eye all the time. Cataract surgery helps you see clearly again.
  • Glaucoma starts with the building up of pressure in the eye. Over time, this pressure damages your eye's main nerve-the optic nerve. The damage first causes you to lose sight from the sides of your eyes. Treating glaucoma is usually simple. Your eye care professional will give you special drops to use every day to lower the pressure in your eyes. Or, your eye care professional may want you to have laser surgery.

This answer is based on source information from the National Institute of Diabetes and Digestive and Kidney Diseases.

Ms. Vandana  R. Sheth
Nutrition & Dietetics Specialist

Unfortunately, uncontrolled blood sugars can affect your vision. If you are diagnosed with diabetes, it is important that you have regular eye exams annually as part of your diabetes management regimen.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.