What causes blood vessels to burst in the eye?

A few days ago I find that there was blood in the white of my eye. Seems like I burst a blood vessel somehow. What could have caused this?

Coughing, sneezing, rubbing your eye. See an ophthalmologist.

Rubbing eye coughing or straining when going to the bathroom. Takes one to two weeks to clear

Straining to go to the bathroom, excessive coughing, or it can occur spontaneously or rubbing the eyes while sleeping. It is harmless, however.

High pressure in your blood vessels and chest, like a cough or sneeze could trigger it