The Red Eye

A red eye is a common complaint in the emergency department (ED) and primary care setting. It can be caused by a wide range of conditions, from minor irritations to serious infections.

The most common causes of red eye in the ED include:

  • Conjunctivitis (pink eye)
  • Subconjunctival hemorrhage (blood in the eye)
  • Corneal abrasion body (scratch)
  • Glaucoma (increased pressure inside the eye)
  • Corneal foreign body
  • Iritis (inflammation of the iris, the colored part of the eye)

A red eye develops following inflammation from a myriad of causes including acute localized infections, chronic disease, allergies, or trauma. Associated symptoms in addition to redness include:

  • Pain
  • Itching
  • Burning
  • Watery discharge
  • Sensitivity to light
  • Blurred vision

Not all red eyes are emergencies, but the following symptoms may indicate a more serious eye condition:

  • severe pain
  • photophobia (sensitivity to light)
  • decreased vision
  • headache
  • stiff neck
  • nausea and vomiting
  • trauma

If you experience any of these symptoms, seek immediate medical attention.

An emergency clinical evaluation may include the following:

  • topical analgesic drops to help with pain
  • visual acuity testing (reading an eye chart)
  • extraocular movement and pupillary evaluation (checking the functionality of your eye muscles)
  • fluorescein stain and slit lamp exam (using a special dye and microscope to magnify and examine the structures of your eye)

Your doctor may also refer you to an ophthalmologist for further evaluation and treatment.

Treatment will vary depending on the underlying cause. For example, conjunctivitis caused by a virus may go away on its own within a few days. However, bacterial conjunctivitis may require treatment with antibiotics.

Corneal abrasions may heal on their own within a few days. However, in some cases, they may require treatment with antibiotic eye drops or ointment.

Uveitis, episcleritis, scleritis, glaucoma, iritis, and optic neuritis are all more serious conditions that require treatment from an eye doctor. Treatment may include anti-inflammatory medications, antibiotics, or steroids.

Oftentimes, prevention is achievable. 

Here are some tips for preventing red eye:

  • Wash your hands frequently with soap and water.
  • Avoid touching your eyes.
  • Remove your contact lenses before going to bed.
  • Use artificial tears to keep your eyes moist.
  • Wear protective eyewear when working outdoors or using tools.

If you have any allergies that can cause red eye, such as pollen allergy, avoid exposure to your allergens whenever possible. 

If you do develop red eye, there are some things you can do at home to relieve your symptoms:

  • Apply a cold compress to your eyes for 10-15 minutes at a time.
  • Use artificial tears to keep your eyes moist.
  • Avoid wearing makeup or contact lenses until your red eye has cleared up.

If your red eye is severe or does not improve with home treatment, be sure to see a doctor.


Biros, M. D., Sterner, S. M., & Vogel, E. C. (2002). Handbook of urgent care medicine (2nd ed.). Haney & Belfus, INC, Medical Publishers.

Tintinalli, J., Kelen, G. D., & Stapczynski, J. S. (2004). Emergency Medicine: A Comprehensive Study Guide (6th ed.). The McGraw Hill Companies, Inc.