A sudden, bright red patch appearing on the white part of the eye can be alarming. This common phenomenon is medically termed a subconjunctival hemorrhage (SCH). It occurs when a tiny blood vessel ruptures just beneath the conjunctiva, the thin, clear membrane covering the sclera (the white of the eye). The resulting blood becomes trapped in this space, creating a visually dramatic red spot. Although the appearance of blood in the eye causes concern, the condition is usually harmless and resolves without intervention.
The Immediate Sensation
A simple subconjunctival hemorrhage typically causes no actual pain, despite the shocking appearance. The conjunctiva contains few sensory nerves, so the vessel rupture often goes unnoticed until the person looks in a mirror. Since the blood is contained on the surface of the eye, vision is not affected, nor should there be discharge or light sensitivity.
The most common sensation reported is a mild feeling of scratchiness or fullness on the eye’s surface. This minor irritation is caused by the slightly raised area of blood under the transparent membrane. If a person experiences significant pain, blurred vision, or discharge, it suggests a different, more serious underlying eye problem.
Common Triggers and Causes
The rupture of these small vessels is frequently caused by a sudden, temporary increase in venous blood pressure in the head. Any action that involves straining can trigger an SCH by causing a Valsalva maneuver (forceful expiration against a closed airway).
Common triggers include intense coughing, forceful sneezing, vomiting, or heavy lifting. Non-strenuous actions, such as aggressive rubbing of the eyes or straining during a bowel movement, can also be responsible.
Underlying health conditions can make a person more susceptible to these ruptures. These factors include hypertension (high blood pressure) and the use of blood-thinning medications like anticoagulants or aspirin, which reduce the blood’s ability to clot.
Healing Time and Management
Healing for a subconjunctival hemorrhage occurs through natural absorption, similar to how the body clears a bruise. The blood is gradually metabolized and absorbed by the surrounding tissues. No external treatment is necessary to speed this process. Depending on the size, the visible blood patch typically resolves completely within one to three weeks.
As the blood is broken down, the color of the patch changes. The initial bright red often darkens, then transitions to a yellowish or brownish hue before disappearing entirely. It is advisable to avoid actions that caused the initial trauma, such as rubbing the eye or straining. Artificial tears may be used if the scratchy sensation is bothersome, but they do not influence the healing timeline.
When to Seek Medical Attention
While most cases of subconjunctival hemorrhage are benign, certain associated symptoms indicate the need for a professional eye examination. Medical advice should be sought immediately if the red spot is accompanied by genuine eye pain or a sudden change in vision. These symptoms are not characteristic of a simple SCH and may point to a more complex injury or condition.
Other red flags include discharge from the eye or increased sensitivity to light. A person should also consult an eye care professional if the hemorrhage occurred after a direct blow or significant trauma to the eye or head. Furthermore, if the condition occurs frequently or does not clear up within the expected three-week timeframe, it may signal an underlying issue. This could include an undiagnosed bleeding disorder or uncontrolled high blood pressure that requires management.