Bloodshot Eyes: Causes, Symptoms & When to See a Doctor

Bloodshot eyes (conjunctival injection) occur when tiny blood vessels on the eye's surface dilate. While often harmless, they can signal conditions needing treatment.

Common Causes

• Allergies: Pollen, dust, pet dander cause itching, watering, redness.
• Infections: Viral or bacterial conjunctivitis (pink eye), often with discharge.
• Dry Eye: Inadequate tears lead to irritation and inflammation.
• Contact Lens Issues: Overwear, poor fit, or poor hygiene.
• Eye Strain: Prolonged screen use reduces blink rate.
• Trauma: Injury, foreign body, or vigorous rubbing.
• Environmental Irritants: Smoke, chlorine, wind, chemicals.
• Subconjunctival Hemorrhage: A bright red patch from a broken vessel; usually painless and harmless.
• Medications: Some blood pressure drugs, anticoagulants.
• Alcohol: Dehydration and vasodilation.

Liver Disease Note

Bloodshot eyes are not a typical direct sign of liver congestion. Jaundice (yellowing of the whites) is the classic ocular sign of liver dysfunction.

When to See an Eye Doctor

• Redness persists >1 week
• Pain, light sensitivity, or vision changes
• Discharge (pus or thick mucus)
• Recent eye injury or surgery
• Associated headache, nausea, or halos around lights (possible glaucoma)