Does Diabetes Cause Blurry Vision?

By Terez Malka, MD
Medically reviewed checkmarkMedically reviewed
September 20, 2022

Diabetes can cause changes to how you see, including eye floaters, blurry vision, and more. In this article, we’ll explore how diabetes affects eye health, short and long-term complications, treatment, and prevention. We’ll also discuss signs that you should see a medical provider.

Diabetes and Blurry Vision: How Diabetes Affects Your Eyes

Diabetes can affect eye health and vision in many ways. The effects can be short-term or long-term. In many cases, blurred vision is a short-term sign that blood sugar is out of balance, either too low or too high. It can sometimes be the first symptom that a person has before diabetes is diagnosed. This can feel like you just can’t quite clear your eyes or like your glasses prescription is slightly off. When blood sugar levels return to normal, so does vision.

High blood sugar and low blood sugar affect vision because they alter how fluids move in and out of the eye. These changes can lead to swelling, and even tiny changes to the eye lens can affect how well the eyes can focus and process light. Low blood sugar may also cause double vision or dimmed vision.

Vision changes can also happen when you start taking a new medication to control diabetes, although the side effect is short-lived.

In some cases, diabetes can cause long-term problems or permanent vision damage, especially if it is not well-controlled. If you have diabetes and notice changes to your vision, let your healthcare provider know right away.

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Long-Term Vision Complications

Diabetes can slowly and progressively worsen eye health, including how well you can see, over time. This is more likely if diabetes is poorly controlled or you develop additional complications.

Possible diabetic eye disease and long-term vision complications in diabetes include the following.

Diabetic Retinopathy

Diabetic retinopathy is a disorder that affects the retina of the eye. It progresses in 4 stages:

  • Stage 1: Mild
  • Stage 2: Moderate
  • Stage 3: Severe
  • Stage 4: Proliferative

Stages 1-3 of diabetic retinopathy do not typically produce noticeable symptoms, and it may be discovered in these stages by a routine eye exam. Stage 4 diabetic retinopathy can include any of the following symptoms, which may continue to worsen over time:

Diabetic retinopathy cannot be cured, and damage that is done cannot be reversed. But eye health can be stabilized with treatment, which may reduce further vision losses. This is why it is very important to get regular eye exams, especially if you have diabetes.

Diabetic Macular Edema

At the center of the retina is the macula, the part of the eye that works to give you crisp vision at the center of your focus.

Macular edema happens when the macula swells. This is caused by fluid leakage. It includes symptoms like blurry vision, wavy vision, or color changes. When macular edema is caused by diabetes, it typically affects both eyes in the same way.

Glaucoma

Glaucoma is an eye disease that occurs when excessive pressure in the eye causes damage to the optic nerve. Diabetes doubles the risk of developing glaucoma.

Signs of glaucoma include:

  • Blurry vision
  • Eye pain
  • Eye redness
  • Seeing halos around lights
  • Tunnel vision
  • Poor peripheral vision
  • Nausea or vomiting

Cataracts

Cataracts occur when proteins in the lens of the eye break down and clump together. These clumps look like clouded spots in the eye and negatively affect vision quality. Cataracts can happen from normal aging processes, but occur more frequently and at younger ages in people with diabetes.

Other signs of cataracts include:

  • Glares or halos around lights
  • Faded colors
  • Cloudy vision
  • Blurred vision
  • Double vision
  • Light sensitivity
  • Vision that does not improve with new glasses prescriptions
  • Prescriptions that change frequently or only work for a short time

Treatment

For people who have diabetes, it is important to maintain regular eye health exams. The best way to treat vision problems is to detect them early. It is also important to manage diabetes well to avoid eye or other health complications.

Eye treatments for diabetes vision problems will depend on the symptoms, the cause, and the severity of the vision issue. Maintaining healthy glucose and blood pressure levels is essential for treating eye problems and preventing further complications and vision loss.

Some treatments for diabetes-related eye problems are:

  • Diabetic retinopathy: Injections to stop swelling, laser surgery, or microsurgery
  • Cataracts: Brighter light, updated glasses prescriptions, or surgery
  • Glaucoma: Prescription eye drops, laser treatments, or surgery
  • Macular edema: Injections or photodynamic therapy

Prevention

Anyone who has diabetes is at an increased risk for vision-related problems. Since there is no cure for most eye complications of diabetes, it is important to prevent them whenever possible. This can be done in the following ways:

  • Utilize diet, lifestyle, and medications to maintain normal blood glucose levels and blood pressure levels.
  • Get regular eye exams.
  • Follow through on all well-checkups and routine health maintenance.
  • Tell your medical provider immediately if you notice any vision changes (even slight).
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When to See a Medical Provider

Blurry vision can be common, and in many cases, it is short-lived. Fatigue, poor sleep, allergies, and outdated glasses prescriptions can all contribute to short-term blurry vision. If you have diabetes, low or high blood glucose levels can cause brief changes to vision.

You should consult a medical provider if you notice vision changes that last longer than a few hours or if they happen consistently for short periods of time. If vision suddenly changes or is accompanied by other symptoms, like confusion, severe headache, or other abnormal signs, seek emergency medical care.

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Frequently Asked Questions

What does blurred vision look like with diabetes?
People describe blurry vision in different ways, but if diabetes is causing it, it may be described as the inability to focus sharply on an object or not being able to see fine details or very small print. You may also notice floaters, strings, spots, or lines in the field of vision or peripheral vision.
What level of blood sugar causes blurry vision?
Blood sugar that is too low can cause blurry vision. This can happen if your levels drop below 70 mg/dL. High blood sugar can also cause blurry vision, which is when levels are higher than 125 mg/dL while fasting or if glucose remains higher than 180 mg/dL two hours after eating.
How can you tell if diabetes is affecting your eyes?
If you have diabetes and notice a sudden change in vision, including blurry vision, it could mean that your blood sugar levels are either too high or too low. The effects usually resolve when blood sugar levels return to normal. Long-term eye health can be affected by diabetes, but these changes happen slowly over time and do not develop suddenly. If you have diabetes, regular eye exams are essential to prevent retinal, macular, or overall eye health complications.
Can vision be restored from diabetes?
If eye health is damaged from diabetes, it cannot be cured or restored, but treating diabetes can prevent further damage. Maintaining normal glucose levels and healthy blood pressure levels are important for protecting healthy eyes and vision.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Terez Malka, MD

Dr. Terez Malka is a board-certified pediatrician and emergency medicine physician.

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