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  • Prairie Eye Care

How Diabetes Affects Eye Health

Diabetes is a chronic health condition where the pancreas does not produce insulin as it should. Insulin is the hormone that regulates blood glucose (sugar) in the body. Left unregulated, people who have diabetes can develop a whole host of health issues, including vision and eye problems. High blood sugar can damage the blood vessels in the eyes, causing complications such as diabetic retinopathy, macular edema, cataracts, and glaucoma. Poorly managed diabetes can lead to vision loss or even blindness. Fortunately, early diagnosis and treatment can protect your eye health and prevent your eyesight from worsening, so regular eye exams are crucial for everyone. This is especially true if you are a person with diabetes. Here are some of the common impacts of diabetes on your eye health.

Diabetic Retinopathy

Diabetic retinopathy is when high blood sugar levels cause damage to blood vessels in the retina - the thin layer of nerve tissue at the back of the eye responsible for visual processing. Diabetic retinopathy usually affects both eyes. When damaged, these blood vessels can swell, leak, or close, eventually losing vision.

Some symptoms of retinopathy include:

  • blurred vision

  • poor night vision

  • blank or dark areas in your field of vision

  • increased "floaters" or spots in your vision

  • trouble seeing colours

  • losing vision

If you have type 2 diabetes, you should be checked immediately for diabetic retinopathy, as often there may be no symptoms during the early stages of the disease. If you have type 1 diabetes, you should be checked within five years of diagnosis and every year at your regular eye exam.

Macular Edema

Left untreated, diabetic retinopathy can develop into diabetic macular edema (DME). DME affects the macula, located at the retina's center. The macula helps you see colours, details, and distant objects and is responsible for central vision. Retinopathy will develop into DME when the retina can no longer absorb the fluids from the leaky blood vessels. As a result, the macula will thicken and swell.


A cataract is when the normally clear lens in the eye becomes cloudy. Imagine looking through a window that's gotten dirty and smudged - this is what your vision will be like with cataracts. Anyone can develop cataracts with age, but people with diabetes tend to develop them earlier, and cataracts progress faster due to high blood sugar. The only way to remove a cataract is with surgery.


Having diabetes almost doubles your chances of developing glaucoma - a serious eye condition that damages the eye's optic nerve that connects the eye to the brain. Glaucoma usually occurs when the eye's drainage system is blocked, and fluid accumulates, creating high pressure in the eye. Left untreated, glaucoma can lead to blindness. There are a few different types of glaucoma, the most common being open-angle and closed-angle. In open-angle glaucoma, the pressure in the eye increases slowly, and vision loss is gradual. In closed-angle glaucoma, this happens suddenly. However, closed-angle glaucoma does not seem to be directly related to diabetes.

Diabetic eye diseases are frequent, and living with diabetes presents unique challenges to your eye health. Managing your blood sugar levels and keeping up with regular eye exams with your optometrist or ophthalmologist will play a key role in protecting your vision.


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