Chemosis occurs when the inner lining of the eyelids swells. This means your eye has become irritated, typically by allergies or as the result of a viral or bacterial infection.

What is chemosis of the conjunctiva?

Chemosis of the conjunctiva is a type of eye inflammation. The condition is more often referred to as “chemosis.” It occurs when the inner lining of the eyelids swells. This transparent lining, called the conjunctiva, also covers the surface of the eye. The swelling of the conjunctiva means your eye has become irritated.

Chemosis is most often related to allergies. Sometimes a viral or bacterial infection may cause it. Chemosis is not contagious — you can’t catch it from another person.

The primary cause of chemosis is irritation. Allergies play a role in eye irritation and chemosis. Seasonal allergies or allergic reactions to pets are the main causes. Animal dander and pollen can make your eyes water, look red, and ooze a white-colored discharge. This condition is called allergic conjunctivitis. You can develop both conjunctivitis and chemosis because of allergies.

Chemosis of the conjunctiva is also associated with angioedema. This is a form of allergic reaction in which your skin swells. Unlike hives — a swelling on the surface of your skin — angioedema swelling occurs underneath your skin.

Eye infections, like viral or bacterial conjunctivitis, can lead to chemosis. You can also have chemosis after eye surgery, or as a result of hyperthyroidism. Hyperthyroidism is a condition in which your thyroid gland overproduces hormones. According to Columbia University’s Edward S. Harkness Eye Institute, some people with overactive thyroids experience eye-related symptoms like chemosis.

Rubbing your eyes too much or too often can also cause chemosis.

Chemosis occurs when the membrane lining your eyes and eyelids accumulates fluid. Symptoms may include:

  • watery eyes
  • excessive tearing
  • itchiness
  • blurry or double vision

You might not be able to close your eyes completely during a bout of chemosis because of the swelling. Some people do not have any symptoms of chemosis other than inflammation.

Call your doctor if you have eye pain or symptoms of a severe allergic reaction. Symptoms of a severe allergic reaction include changes in breathing or heart rate, wheezing, and swelling of the lips or tongue.

Your eye doctor can most often diagnose chemosis by doing a physical examination of the affected eye(s). Your eye doctor may ask questions about the length and severity of your symptoms. Give detailed information about your symptoms and allergies. This will help your doctor find the best treatment.

The key to treating chemosis is to reduce inflammation. Managing the swelling can reduce discomfort and negative impact on your vision. Placing cool compresses over your eyes may ease discomfort and inflammation. Your doctor may also tell you to stop wearing contact lenses during treatment.

Further treatment may depend on the cause of your chemosis.


If chemosis is caused by allergies, your doctor may recommend antihistamines. These medications reduce your body’s reaction to allergens. An allergen is a substance that your body sees as harmful. When your body encounters an allergen, like dust or pet dander, it produces histamines to fight off the perceived intruder. Antihistamines can help suppress this immune response and reduce symptoms like irritation and swelling. Try to stay away from known allergens like pollen, pet dander, and smoke.

An over-the-counter oral antihistamine, like Claritin (loratadine), is usually strong enough to treat chemosis inflammation due to allergies. Let your doctor know if these medications are not effective. You may need a prescription for stronger medications.

Bacterial infection

Your doctor may prescribe medicated eye drops to lubricate your eyes. Depending on the severity of your condition, you may need over-the-counter eye drops.

Bacterial conjunctivitis is treated with antibiotic ointments or eye drops. If you show symptoms of a bacterial infection, take the full course of medication. This will prevent the infection from recurring.

Viral infection

Viral conjunctivitis is another potential cause of chemosis. However, antibiotics don’t treat viral infections. Cold compresses and lubricating eye drops are often the best treatments for this type of infection.

Your outlook depends on the cause and severity of chemosis. If you treat the underlying cause you should make a full recovery.

In some cases, such as after eye surgery, chemosis may not be preventable. However, if chemosis is caused by allergies, taking steps to avoid them and managing symptoms can reduce the risk for recurring bouts of chemosis. Practice good hand washing to prevent the spread of bacteria. Also, avoid excessively touching or rubbing your eyes, especially with dirty hands.