A subconjunctival hemorrhage (sub-kun-JUNK-tih-vul HEM-uh-ruj) occurs when a tiny blood vessel breaks just underneath the clear surface of your eye (conjunctiva).
You may not realize you have a subconjunctival hemorrhage until you look in the mirror and find the white part of your eye is bright red.
The conjunctiva can't absorb the blood very quickly, so the blood is trapped under this transparent surface. A subconjunctival hemorrhage may worry you, but it's usually a harmless condition that disappears within one or two weeks.
Subconjunctival hemorrhage often occurs without any obvious harm to your eye, or it may be the result of a strong sneeze or cough that caused a blood vessel to break. You don't need any specific treatment for a subconjunctival hemorrhage.