A bloody eye can be caused by a blood vessel that leaks underneath the white part of your eye (conjunctiva). It causes alarm, but most cases do not require treatment and do not threaten vision. 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 and constipation
- Blood thinners such as aspirin (acetylsalicylic acid) and warfarin (one brand name is Coumadin)
- Rarely, a blood clotting disorder or vitamin K deficiency (vitamin K aids the functioning of proteins necessary for blood clotting)
- Eye surgery, including LASIK and cataract surgery
- Lubricant artificial tears and cold packs can soothe the eyes, although eye drops cannot help repair the broken blood vessels.
- If you are taking aspirin or blood thinners, continue taking them unless your doctor specifically instructs you to do otherwise.
Make sure not to rub your eye, which can increase the risk of re-bleeding right after onset — similar to how a nose bleed is susceptible to re-bleeding in the early stages.