Source:allaboutvision
When small, delicate blood vessels break beneath the tissue covering the white of the eye (conjunctiva), resulting eye redness may mean that you have a subconjunctival hemorrhage.
A subconjunctival hemorrhage usually is benign, causing no vision problems or significant eye discomfort despite its conspicuous appearance.
But eye redness also can be a sign of other types of potentially serious eye conditions. Particularly if you have eye discharge, you should visit your eye doctor for an eye exam to rule out an infection caused by bacteria, virus or other micro-organism.
You should seek immediate care from an eye care professional whenever you experience unusual and persistent redness of the eye accompanied by a sudden change in vision, pain or strong light sensitivity. This type of eye redness can be a sign of other eye problems such as sudden onset of glaucoma.