A sudden, bright red spot appearing on the white part of the eye is medically known as a subconjunctival hemorrhage. This condition occurs when tiny blood vessels break beneath the conjunctiva, the thin, clear membrane covering the sclera. The blood leaks out and becomes trapped between this clear layer and the underlying sclera, creating a starkly visible red patch. Despite its dramatic appearance, a subconjunctival hemorrhage is typically a benign event confined to the surface of the eye. It rarely affects a person’s vision or causes any pain.
Physical Stressors and Direct Trauma
The most frequent cause of a broken blood vessel in the eye is a momentary, sharp increase in pressure within the veins of the head and neck. This pressure spike forces the rupture of the delicate, superficial capillaries located in the conjunctiva. Any physical action that involves straining or holding one’s breath against a closed airway can trigger this mechanism, known as the Valsalva maneuver. Common examples include a severe fit of coughing or a forceful sneeze that rapidly elevates thoracic and abdominal pressure.
Strenuous physical activity, such as heavy weightlifting or intense straining during a bowel movement, can also transmit sufficient pressure to the fragile ocular vessels. The sudden, forceful expulsion of air or matter, like repeated vomiting, represents another mechanical cause for the rupture.
Minor direct trauma to the eye is also a frequent mechanical cause, particularly in younger individuals. This can range from an accidental poke from a finger to vigorous rubbing of the eyes, which puts direct pressure on the conjunctival surface. Improper handling or poorly fitting contact lenses can also lead to localized irritation and vessel damage.
Systemic Health Conditions and Medications
Underlying medical conditions can weaken the resilience of the blood vessel walls, making them susceptible to rupture even without significant physical strain. Uncontrolled hypertension, or high blood pressure, is one such factor, as the constant, elevated pressure weakens vascular integrity over time. This chronic stress can lead to spontaneous hemorrhages or make the vessels more prone to breaking from a minor pressure change. Managing high blood pressure is important for reducing the risk of recurrent episodes.
Certain medications designed to alter the body’s clotting ability significantly increase the likelihood of a subconjunctival hemorrhage. Anticoagulant or antiplatelet drugs, such as aspirin, warfarin, or newer direct oral anticoagulants, prevent the blood from clotting normally. If a vessel breaks, these medications allow the blood to leak out more extensively before coagulation stops the flow, resulting in a larger red patch.
Conditions that directly impair the body’s ability to form clots, such as rare bleeding disorders or certain blood dyscrasias, can also manifest as subconjunctival hemorrhages. Diabetes mellitus is another systemic condition implicated, as it can compromise the health and structure of small blood vessels throughout the body. When a hemorrhage occurs in a person with these underlying issues, it may signal a need for better management of the systemic condition.
Recovery Timeline and Warning Signs
An uncomplicated subconjunctival hemorrhage is a self-limiting condition that requires no specific medical treatment. The body naturally reabsorbs the leaked blood over a period comparable to a bruise healing on the skin. Resolution typically takes between seven and fourteen days, though larger hemorrhages may persist for up to three weeks.
As the blood is broken down, the color of the patch will gradually transition. The initial bright red will often darken to a maroon or brownish hue, eventually fading to a yellowish tint before disappearing. Throughout this process, vision should remain unaffected, and the eye should not experience any significant discomfort beyond a possible mild, gritty sensation.
A visit to an eye care specialist is warranted if the hemorrhage is accompanied by certain red flags, indicating a potentially more serious issue. These warning signs include any sudden change or loss of vision, the onset of eye pain, or noticeable light sensitivity. If the bleeding occurs following a significant blow to the head or eye, or if the red spot fails to shrink after three weeks, a comprehensive eye examination is necessary. Frequent, unexplained recurrence should also prompt a medical evaluation to screen for underlying systemic disorders like uncontrolled hypertension or an undiagnosed bleeding tendency.