Eye redness is most often due to swollen or dilated blood vessels. This makes the surface of the eye look red or bloodshot.
Bloodshot eyes; Red eyes; Scleral injection; Conjunctival injection
There are many causes of a red eye or eyes. Some are medical emergencies. Others are a cause for concern, but not an emergency. Many are nothing to worry about.
Eye redness is often less of a concern than eye pain or vision problems.
Bloodshot eyes appear red because the vessels at the surface of the white portion of the eye (sclera) become swollen. Vessels may swell due to:
Eye infections or inflammation can cause redness as well as possible itching, discharge, pain, or vision problems. These may be due to:
Other potential causes of eye redness include:
Sometimes, a bright red spot, called a subconjunctival hemorrhage, will appear on the white of the eye. This often happens after straining or coughing, which causes a broken blood vessel on the surface of the eye. Most often, there is no pain and your vision is normal. It is almost never a serious problem. Because the blood leaks into the conjunctiva, which is clear, you cannot wipe or rinse the blood away. Like a bruise, the red spot will go away within a week or two.
Try to rest your eyes if redness is due to fatigue or eye strain. No other treatment is needed.
If you have eye pain or a vision problem, call your eye doctor right away.
Go to the hospital or call your local emergency number (such as 911) if:
Call your health care provider if:
Your provider will perform a physical exam, including an eye exam, and ask questions about your medical history. Questions may include:
Your provider may need to wash your eyes with a saline solution and remove any foreign bodies in the eyes. You may be given eye drops to use at home.
Mannis MJ, Plotnik RD. Bacterial conjunctivitis. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology 2013 edition. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 4, chap 5.
Rubenstein JB, Tannan A. Conjunctivitis: infectious and noninfectious. In: Yanoff M, Duker JS, eds. Ophthalmology. 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 4.6.
Wright JL, Wightman JM. Red and painful eye. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 22.