A subconjunctival hemorrhage occurs when small, delicate blood vessels break beneath the tissue covering the white of the eye (conjunctiva), resulting in eye redness/blood. A subconjunctival hemorrhage usually is benign, causing no vision problems or significant eye discomfort despite its conspicuous appearance. Although it is not always possible to identify the source of the problem, some potential causes of subconjunctival hemorrhage include: eye trauma; a sudden increase in blood pressure that can result from heavy lifting; coughing; sneezing; laughing or straining; blood thinners such as aspirin and warfarin (Coumadin); and rarely, a blood clotting disorder or vitamin K deficiency. A subconjunctival hemorrhage usually resolves without treatment within 1 to 3 weeks of onset.