Subconjunctival hemorrhages are small accumulations of blood beneath the conjunctiva (the membrane that lines the eyelid and covers the front of the eye). Sometimes the whole eye appears red and sometimes only a part appears red. The blood comes from small blood vessels on the surface of the eye, not from inside the eye. Because the blood does not involve the cornea (the clear layer in front of the iris and pupil) or the interior of the eye, vision is not affected.
Subconjunctival hemorrhages usually result from minor injury to the eye, straining, lifting, pushing, bending forward, vomiting, sneezing, coughing, or eye rubbing (gentle or vigorous). Rarely, they occur spontaneously. Subconjunctival hemorrhages may appear frightening but are almost always harmless.
Subconjunctival hemorrhages disappear on their own, usually within 2 weeks. No treatment is helpful or necessary. A subconjunctival hemorrhage often occurs together with a black eye.