Chemosis is swelling of the tissue that lines the eyelids and surface of the eye (conjunctiva).

Fluid-filled conjunctiva; Swollen eye or conjunctiva

Chemosis is a sign of eye irritation. The outer surface of the eye looks like it has fluid in it. Often, the eye area swells so much that you can't close your eyes properly.

Chemosis is often related to allergies or an eye infection. Chemosis can also be a complication of eye surgery, or it may occur from rubbing the eye too much.

• Angioedema
• Allergic reaction
• Bacterial infection (conjunctivitis)
• Viral infection (conjunctivitis)

Over-the-counter antihistamines and cool compresses placed on the eyes may help relieve symptoms due to allergies.

If symptoms continue, or if you have a painful and red eye, see your health care provider.

Call your health care provider if:

• Your symptoms do not go away
• You have other symptoms, such as eye pain, change in vision, difficulty breathing, or fainting

The health care provider will perform a physical exam and ask questions about your symptoms, which may include:

• When did it start?
• How long does the swelling last?
• How bad is the swelling?
• How much is the eye swollen?
• What, if anything, makes it better or worse?
• What other symptoms do you have? (For example, breathing problems)

Your health care provider may prescribe an eye medication to reduce swelling and treat any conditions that may be causing the chemosis.

Chapin MJ, Win PJ, Abelson MB. Mediators of ocular inflammation. In: Tasman W, Jaeger EA, eds. Duane's Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 27.

Karesh JW, On AV, Hirschbein MJ. Noninfectious orbital inflammatory disease. In: Tansman W, Jaeger EA, eds. Duane's Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 35.

Rubenstein JB, Virasch V. Conjunctivitis: infections and noninfections. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier; 2008:chap 4.6.

Rubenstein JB, Virasch V. Allergic conjunctivitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier; 2008:chap 4.7.