What Causes A Blood Red Eye?

A blood red eye can be quite alarming when it suddenly greets you in the mirror one morning. Fortunately, most of the time it will turn out to be much less serious than it appears. The white tissue on the front of the eye is known as the sclera. Overlying this is a clear transparent thin layer that is loosely attached to the sclera, the conjunctiva. Because the connection is so loose between the layers, an empty potential space exists. There are tiny blood vessels that transverse through this tissue and they can be somewhat fragile. If a blood vessel ruptures, the blood will spread out and fill the empty space. It will often cover a large part of the white of the eye with a blood red appearance. These are referred to as sub-conjunctiva hemorrhages.

A number of issues can lead to these hemorrhages on the eye.

  • Mechanical trauma to the blood vessels can cause them to rupture. Simply rubbing the eyes can be enough force to break the tiny blood vessels on the eye. A foreign object or blow to the eye is a frequent antecedent. Sports like basketball where fingers frequently end up in an eye can certainly give you a broken conjunctiva blood vessel. Protective sports eye wear can prevent these incidents and many much more serious eye injuries.
  • Centripetal force or the feeling of weightlessness occurs on roller coasters, merry go rounds, bungee jumping, flying maneuvers, and extreme sports of all flavors (intentional or accidental!). The blood flow is increased towards the head and the increased blood volume can result in an blood red eye.
  • Anything that increases the resistance to blood drainage in the blood veins frequently is found in the history of sub conjunctiva hemorrhages. Coughing, vomiting, even straining with constipation can temporarily raise the resistance to blood drainage in the fragile capillaries of the eye tissues. Lifting weights while holding your breath and even childbirth can alter the blood flow in the veins.

If you develop an eye with the appearance of blood you should immediately seek care from your optometrist. Rarely there can be other problems that require intervention. Problems and diseases of the blood can cause recurrent hemorrhages. People on blood thinners, regular use of aspirin, and some other medications are at an increased risk for blood vessels bleeding. Some forms of eye infections will cause numerous hemorrhages, and often in both eyes. Conditions like diabetes and high blood pressure can make the eye more susceptible to breaks in the blood vessels.

Usually the cure is time. These conjunctiva hemorrhages will follow a course similar to a bruise on your skin, often taking three to six weeks to resolve. They also will undergo color changes from bright red to purple before fading away. This is one eye condition where the appearance is fortunately much worse than the outcome!