How Diabetes Can Affect Your Eyes and Vision

Dec 15, 2022
How Diabetes Can Affect Your Eyes and Vision
Diabetes, characterized by high blood sugar levels, can damage your eyes and affect your vision. Keep reading to learn what can happen and how you can prevent problems from developing.

Diabetes is a disease characterized by high blood sugar levels. In 2018, it affected some 34.2 million Americans — 10.5% of the population! About 90-95% of adult cases were type 2, in which the body becomes resistant to the effects of the hormone insulin, responsible for transporting glucose from the blood into the cells, where it’s converted into energy.

At Precision Eye Institute, ophthalmologist Dr. Orest Krajnyk and optometrist Dr. Sean McLoughlin and their team offer comprehensive eye exams to check, in part, for the earliest stages of eye disease, when they’re more easily treated successfully.

Diabetic eye exams focus on preventing complications from high blood sugar and can help save your sight. If you have diabetes or are at risk for developing it, here’s what you need to know about how the disease can affect your eyes.

Eye basics

Before you can understand how and why diabetes affects your vision, it helps to know something about how the eye is structured. We can get that information from the path that light takes. 

Incoming light first hits the eye’s surface, which is covered with a clear, curved membrane. The clearness allows the light through. The curved area (cornea) focuses that light while also protecting the eye from pathogens and environmental debris.

The focused light heads through the anterior chamber, an area filled with a liquid called aqueous humor. Next, it goes through the pupil, and then through a clear lens, which refines the focus. Finally, it travels through another fluid-filled chamber, the vitreous, hitting the retinal tissue at the back of the eye.

The retina takes the focused light and converts it into electrical signals, sending them to the brain through the optic nerve. Your brain translates the signals, producing the image you see.

The central region of the retina, which makes up about 2% of the total tissue, is called the macula. It’s nourished by blood vessels within and behind the retina and provides you with your clear, central vision.

Some common diabetic eye health problems

When you come in for an eye exam and you’re a diabetic, your doctor evaluates both your vision and your eye health, just as with a regular comprehensive exam. But the doctor pays special attention to the areas that diabetes typically damages. 

High blood sugar levels can lead to eye problems ranging from blurry vision to total blindness. That’s why it’s so important to get a professional eye exam at least once a year. Some of the major diabetes-related problems affecting the eyes include:

Nonproliferative diabetic retinopathy (NPDR)

Diabetic retinopathy affects more than 1 in 4 American adults living with diabetes, and it’s a major cause of blindness.

In the early stages of NPDR, blood vessels weaken, bulging into the retina or leaking blood into the surrounding tissue. As a result, lipids (fats) can be deposited on the retina, obscuring vision. In the late stages of NPDR, the macula swells (macular edema), leading to further blurred vision.

Proliferative diabetic retinopathy (PDR)

As retinopathy progresses, blood vessels can seal themselves off, preventing oxygen and nutrients from reaching and nourishing the macula. 

The result is that new vessels proliferate on the retinal surface, leading to mild problems such as visual floaters, or major problems such as scar tissue buildup and/or a detached retina, causing vision loss.


Glaucoma is a collection of eye conditions that damage the optic nerve and prevent it from sending visual information to the brain. High blood sugar levels prevent the eyes from draining properly, and the increased pressure inside your eye leads to nerve damage.

Many forms of glaucoma have no observable signs until they reach an advanced stage, and once you lose vision, you can’t get it back. That’s another reason why regular diabetic eye exams are so important.


Cataracts occur when the clear lens in the eye clouds over with debris. They’re a common problem, especially as you get older, but diabetics often develop them earlier than the average person, and they get worse faster. Replacing the lens can correct the problem.

If you have diabetes, or if you’re at risk for developing it, it’s crucial that you get regular eye exams to prevent problems from developing. Schedule your appointment with Precision Eye Institute by calling or booking online with us today. We have offices in Edgewater, New Smyrna Beach, and Daytona Beach, Florida.