Symptoms
The most obvious sign of a subconjunctival hemorrhage is a bright red patch on the white (sclera) of your eye.
Despite its bloody appearance, a subconjunctival hemorrhage should cause no change in your vision, no discharge from your eye and no pain. Your only discomfort may be a scratchy feeling on the surface of your eye.
When to see a doctor
If you have recurrent subconjunctival hemorrhages or other bleeding, talk to your doctor.
Source: http://www.mayoclinic.com