A subconjunctival haemorrhage occurs when a tiny blood vessel breaks just underneath the clear surface of your eye called conjunctiva. It is identical to an ordinary bruise on the skin. It normally appears as a single, concentrated spot of red, or many scattered red splotches, on the white of the eye. The redness is blood under the conjunctiva, a clear membrane that covers the white of the eye and the inner eyelids. You may be unable to recognise a subconjunctival haemorrhage until you look in the mirror and find the white part of your eye is bright red.
While it can be alarming to awaken to what appears to be a bleeding eye, a subconjunctival haemorrhage is usually harmless, with the visible blood resulting from a simple broken blood vessel.
Causes of subconjunctival haemorrhage
Causes of subconjunctival haemorrhage are not always known. The following reasons may contribute to the rupture of a small blood vessel in your eye:
If you have persistent or excessive 
subconjunctival haemorrhages, your ophthalmologist will examine your eyes, assess your risk factors and order suitable tests in collaboration with your family doctor.
Symptoms of subconjunctival haemorrhage
A visible symptom of subconjunctival haemorrhage is a bright red patch on the white (sclera) of your eye. In spite of the bloody appearance, a subconjunctival haemorrhage should cause no change in your
vision, no pain and no discharge from your eye. Only discomfort may be a scratchy feeling on the surface of your eye.
Treatment of subconjunctival haemorrhage
Visible blood in your eye due to subconjunctival haemorrhage will be slowly reabsorbed by your body. Most resolve within about seven days without treatment. A large subconjunctival haemorrhage, however, can take up to two to three weeks to go away. The redness may turn to an orange colour, then pink and then white again. Your eye will not be stained by the blood. If your eye is irritated, your 
ophthalmologist may recommend that you use over-the-counter
artificial tears.
Additional information on subconjunctival haemorrhage
If you are concerned about bleeding in your eye, schedule an 
eye examination. Your ophthalmologist will complete a careful medical history to rule out potential causes of the
haemorrhage. Your eyes will be checked to ensure that the eye is intact and no other injuries may have occurred to other structures of the eye. Even though the appearance of blood in your eye can be disturbing, it is not an alarming situation, especially if there is no pain or visual changes.