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How Can Blood Glucose Levels Affect Vision?

Diabetes impact on eye health

As November is National Diabetes and Diabetic Eye Disease Awareness Month, we’re taking the time to discuss how diabetes affects vision and what you can do to best protect your sight.

Diabetic eye disease is a leading cause of blindness that often has no early warning signs. For diabetic individuals, high blood sugar can cause the lens of the eye to swell and change the ability to see. This type of blurred vision can also be a symptom of more serious eye problems, so it is imperative that they work with their doctor to ensure their blood sugar is back in the recommended range.

According to the American Diabetes Association, people with diabetes should follow the below guidelines for eye exams:

  • Adults with type 1 diabetes should have a full dilated eye exam within 5 years of their diagnosis
  • Adults with type 2 diabetes should have a complete eye exam soon after they have been diagnosed
  • Individuals who are pregnant or planning to get pregnant should get a dilated eye exam

Along with following these guidelines, it is also important to know what diseases are most common with diabetes and how to best treat them.

Diabetic retinopathy

The most common diabetic eye disease, diabetic retinopathy is a leading cause of blindness. Caused by high levels of blood glucose, it is characterized by the leaking of blood vessels in the retina. Diabetes can cause blood vessels to swell and leak fluid, posing significant risk for diabetic retinopathy. This disease is often treated with laser and medications. If these methods are not possible, due to dense and persistent vitreous hemorrhage in the eye, then vitrectomy surgery is the preferred treatment. This technique allows the doctor to clean away the vitreous blood and apply a laser to prevent future bleeding.


While anyone can get a cataract, individuals with diabetes can get cataracts at an earlier age. A clouding of the lens of the eye, making it unable to focus, cataracts tend to progress more quickly for diabetics. This means diabetics can experience a quicker deterioration of their lens, and subsequently their eyesight. The treatment option for cataracts is surgery, where the old lens is removed and replaced with a clear lens.


Glaucoma is caused by an increase in the intraocular pressure, or the pressure on the inside of the eye. This increased pressure can damage the optic nerve, causing permanent vision loss. People with diabetes can get a less common type of glaucoma called neovascular glaucoma. In this form, new blood vessels grow into the iris of the eye and block the normal flow of aqueous which raises intraocular pressure. Treatment for glaucoma is often initially eye drops, followed by specific laser treatment options.


At ReFocus, we are thankful for an expert team of ophthalmologists and optometrists, many who specialize in diabetic vision diseases. If you are seeking more information about diabetic eye diseases, or would like to schedule an appointment, contact our experts today.