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Definition

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

Alternative Names

Fluid-filled conjunctiva; Swollen eye or conjunctiva

Considerations

Chemosis is a sign of eye irritation. The outer surface of the eye (conjunctiva) may look like a big blister. It can also look like it has fluid in it. When severe, the tissue 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.

Causes

Causes may include:

Home Care

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

When to Contact a Medical Professional

Call your health care provider if:

  • Your symptoms do not go away.
  • You can't close your eye all the way.
  • You have other symptoms, such as eye pain, change in vision, difficulty breathing, or fainting.

What to Expect at Your Office Visit

The 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 provider may prescribe eye medicine to reduce swelling and treat any conditions that may be causing the chemosis.

Gallery

Chemosis
Chemosis is swelling of the eye surface membranes because of accumulation of fluid. This symptom is often related to an allergic response. Over-the-counter antihistamines, and a cool cloth placed over the eyes, are usually used to try to alleviate the symptoms.

References

Fernandez A, Asbell P, Roy N. Emerging therapies targeting eosinophil-mediated inflammation in chronic allergic conjunctivitis. Ocul Surf. 2022;26:191-196. PMID: 35970432 pubmed.ncbi.nlm.nih.gov/35970432/.

Kumar NM, Barnes SD, Pavan-Langston D, Azar DT. Microbial conjunctivitis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 112.

McNab AA. Orbital infection and inflammation. In: Yanoff M, Duker JS, eds. Ophthalmology. 6th ed. Philadelphia, PA: Elsevier; 2023:chap 12.14.

Rubenstein JB, Kelly E. Infectious conjunctivitis. In: Yanoff M, Duker JS, eds. Ophthalmology. 6th ed. Philadelphia, PA: Elsevier; 2023:chap 4.6.

Last reviewed April 29, 2025 by Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

Related specialties

Clinical trials: Chemosis

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