Eye redness, also known as bloodshot eyes, occurs when blood vessels are visible on the sclera or the white part of the eye. Eye redness can be caused by numerous factors, including irritants such as cigarette smoke or dust that can enter the eye and cause the blood vessels to swell.
Other causes of eye redness include allergies, the wearing of contact lenses for prolonged periods, and chronic conditions such as glaucoma or an eye ulcer. Conjunctivitis, which is an infection of the outer layer of the eye, can also cause redness. The sclera can also be affected by infection or injury that causes the underlying blood vessels to burst. This can be the result of innocuous actions, such as forcefully rubbing the eyes or sneezing.
