Amy Campbell, CDE, is a registered dietitian and the author of several books about diabetes, including 16 Myths of a Diabetic Diet and Staying Healthy with Diabetes: Nutrition and Meal Planning.

One morning, you wake up and your eye barely opens because it’s crusted over. When you’re finally able to pry it open, you look in the mirror and the white of your eye is pink. You have a goopy discharge in the corner of your eye. Your eye might feel itchy or burn. What’s going on? You probably have “pink eye,” otherwise known as conjunctivitis. And there’s a good chance that having diabetes might just be the culprit.

What is conjunctivitis?

According to the American Optometric Association, conjunctivitis is “an inflammation or swelling of the conjunctiva.” The conjunctiva is the thin lining of tissue that covers the white of the eye and that also lines the inside of the eyelid.

What causes conjunctivitis?

There are several possible causes of pink eye:

Viruses. A number of different types of viruses can lead to conjunctivitis, such as adenoviruses. You may have viral conjunctivitis if your eye discharge is watery.

Bacteria. Several types of bacteria can cause bacterial conjunctivitis, including Staphylococcus aureus and Streptococcus pneumonia. A thick, greenish-yellow discharge may indicate bacterial conjunctivitis. This type is more common in children than adults.
Note that both viral and bacterial types of conjunctivitis are highly contagious, and may affect both eyes.

Allergies. An allergen, such as pollen, dust mites, pet dander, or cosmetics can trigger this type of non-contagious conjunctivitis. This occurs due to a release of histamine, which can cause other allergy symptoms as well. You might have intense itching in your eyes and a watery discharge, accompanied by sneezing and a runny nose.

Irritants. A chemical that splashes into your eye or a foreign object may cause this type of conjunctivitis. It may also result from wearing contact lenses for too long. It, too, is not contagious and may clear up on its own.

What are the symptoms?

Some of the most common symptoms of conjunctivitis include:

  • Redness of the eye
  • Swelling of the white of the eye
  • Watery eyes
  • A white, yellow, or greenish discharge
  • Crusting of the eyelids or eyelashes
  • Itchy, irritated, and/or burning eyes
  • A gritty feeling in the eye
  • Sensitivity to light

How does diabetes play a role?

Researchers at the University of Surry in Guildford, England studied a population of 938,440 individuals without diabetes and 48,584 individuals with either type 1 or type 2 diabetes. The people who had diabetes had a significantly increased incidence of conjunctivitis (but not other types of eye infections). This increased risk wasn’t linked to hyperglycemia, however.

How is conjunctivitis treated?

While many cases of conjunctivitis clear up on their own, you should see your primary care doctor or an eye doctor if you have:

  • Pain in your eye
  • Sensitivity to light
  • Blurry vision
  • Extreme redness in your eye
  • A weakened immune system
  • A pre-existing eye condition

Also, seek medical attention if your symptoms don’t clear up after 24 hours or if they get worse.
If your provider determines that you have viral conjunctivitis, the treatment is to let the infection run its course. However, if you have a herpes simplex infection, you may be given an antiviral medication. Be aware that the infection may affect your other eye. It may take a week or two for the infection to clear.

Bacterial conjunctivitis, too, can often clear up on its own, although your doctor may prescribe an antibiotic ointment or eye drops.

Allergic conjunctivitis is usually treated with antihistamines, decongestants, and/or steroids in the form of eye drops.

While you wait for your infection to clear, you might also try the following home remedies:
- A warm or cool compress applied to your closed eyelid several times a day. Don’t touch the cloth to your other eye if it’s not infected.
- Artificial tears may make you more comfortable. Choose those that are preservative free. Avoid decongestant eye drops that “take the red out,” as they can cause rebound redness after a while.
- Leave your contact lenses out until your infection heals.
- Don’t wear eye makeup, such as mascara, liner, or eye shadow. (It’s a good idea to throw your eye makeup out to prevent reinfecting yourself.)
- Wash your clothes, your towels, and your bed linens frequently.

How can you avoid getting conjunctivitis?

  • Don’t share towels or tissues.
  • Never share contact lenses or eye makeup with others.
  • Wash your hands frequently.
  • Don’t rub or touch your eyes.
  • Keep surfaces in your home clean, including bathroom vanities, kitchen counters, faucets, and phones.
  • Keep a hand disinfectant with you, especially when you’re out in public.
  • Wear swim goggles when swimming. Bacteria can lurk in the water.

Have you had conjunctivitis? Did it require medical treatment? Add a comment below and tell us about your experience.