Eye health resource
Diabetes and Its Effects on Your Eyesight
Learn how diabetes can affect vision and eye health, including temporary blur, diabetic retinopathy, diabetic macular edema, cataracts, and the importance of regular eye exams.
Reviewed for accuracy by Justin Bazan, OD on .
Diabetes can affect vision in more than one way. Some changes are temporary, while others can threaten sight if they are not detected and managed early.
The important thing to know is that diabetic eye disease can develop before you notice symptoms. Regular eye examinations are therefore an important part of diabetes care even when your vision seems normal.
Why can blood sugar changes make vision blurry?
Changes in blood glucose can temporarily affect the eye’s focusing system. Some people notice fluctuating blur when glucose levels are changing substantially.
That does not automatically mean there is permanent eye damage, and it does not always mean that a new glasses prescription is the right first step. If your vision is fluctuating along with poorly controlled or rapidly changing blood sugar, it is worth discussing both with your medical doctor and your eye doctor.
What is diabetic retinopathy?
The retina is the light-sensitive tissue at the back of the eye. Over time, diabetes can damage its small blood vessels. This is called diabetic retinopathy.
Early diabetic retinopathy may cause no noticeable symptoms. As disease progresses, damaged blood vessels can leak, close off, or stimulate abnormal new blood-vessel growth. Vision can become blurred, distorted, or reduced, and advanced disease can lead to serious vision loss.
What is diabetic macular edema?
The macula is the central part of the retina used for detailed vision, such as reading and recognizing faces. Diabetes can cause fluid to leak into this area, producing diabetic macular edema (DME).
DME can cause central blur or distortion and can occur at different stages of diabetic retinopathy.
Does diabetes increase the risk of other eye problems?
Yes. Diabetes is also associated with a higher risk of several other eye conditions, including cataracts and glaucoma.
A comprehensive diabetic eye evaluation therefore looks at more than one possible complication.
What symptoms should prompt an eye exam?
Contact your eye doctor if you have diabetes and notice symptoms such as:
- new or worsening blur
- spots, floaters, or dark areas in the vision
- distortion
- difficulty reading or seeing fine detail
- noticeable changes in color or contrast
- unexplained changes in one or both eyes
Sudden vision loss, a sudden shower of new floaters, flashes, a curtain or shadow in the vision, or significant eye pain should be treated as urgent symptoms rather than waiting for a routine appointment.
How are diabetic eye problems detected?
Evaluation may include visual acuity, a careful examination of the retina and optic nerve, and additional imaging when clinically appropriate. Depending on the findings, retinal photography, OCT, dilation, or other testing may be recommended.
Because important diabetic changes can occur without symptoms, the goal is not merely to investigate blur—it is also to identify disease early enough to protect vision.
Can diabetic eye disease be treated?
Yes. Treatment depends on the type and severity of the problem. Some patients only need close monitoring and better control of systemic risk factors. More advanced diabetic retinopathy or diabetic macular edema may require treatment by a retinal specialist, such as injections, laser treatment, or surgery.
Park Slope Eye can evaluate diabetic eye health and, when specialty treatment is needed, refer or co-manage appropriately. Our Medical Eye Care page explains that role in more detail.
What can you do to lower your risk?
Good diabetes care matters to eye health. Work with your medical team on blood sugar, blood pressure, cholesterol, smoking cessation when relevant, and other individualized risk factors. Keep the eye-exam schedule recommended for you rather than waiting for vision changes.
If you want a focused answer about whether existing diabetic-retinopathy damage can improve, see our separate article, Can Diabetic Retinopathy Be Reversed?.
The key point: diabetes can affect both vision and eye health in ways that may be silent at first. Regular, appropriately timed eye care is one of the best ways to catch problems before they become harder to manage.