What causes red eyes?
Feb 13, 2025
Source: Cainiu Health
Dr. Wang Shuai
Introduction
Red eyes may be caused by excessive eye strain, lack of sleep, conjunctivitis, keratitis, scleritis, or other reasons. If you experience any discomfort, seek medical attention promptly and undergo symptomatic treatment under the guidance of a qualified physician. In daily life, maintain a balanced diet and consume more foods rich in vitamins A, C, and E, such as carrots, oranges, and blueberries, which help support eye health.
Generally, red eyes may be caused by overuse of the eyes, lack of sleep, conjunctivitis, keratitis, scleritis, or other conditions. If you experience any discomfort, seek medical attention promptly and undergo symptomatic treatment under the guidance of a qualified physician. Detailed explanations are as follows:
1. Eye Strain
Prolonged close-up work, such as staring at computer or phone screens or reading books, can cause the eye's ciliary muscles to remain contracted for extended periods, affecting local blood circulation and resulting in red eyes. It is recommended to manage eye usage time reasonably; rest for 5–10 minutes after every 45 minutes to 1 hour of eye use, look into the distance to relax the eyes, and maintain proper posture. Adjust screen height and angle to reduce eye strain.
2. Lack of Sleep
Chronic sleep deprivation can impair the eye's self-repair mechanisms, leading to dilation of ocular blood vessels and blood congestion, which can cause red eyes. Maintain a regular sleep schedule in daily life, ensuring 7–8 hours of quality sleep each day. Develop good sleeping habits, avoid strenuous exercise and electronic device use before bedtime, and create a quiet and comfortable sleep environment.
3. Conjunctivitis
Conjunctivitis is commonly caused by viral or bacterial infections or allergic factors. Inflammation can cause conjunctival blood vessels to dilate and become congested, leading to red eyes. Symptoms may also include nasal itching and sneezing. Treatment may include antibiotic or antiviral eye drops such as levofloxacin eye drops, tobramycin eye drops, or acyclovir eye drops, as directed by a physician.
4. Keratitis
Keratitis often occurs after corneal injury followed by infection with bacteria, viruses, fungi, or other pathogens. Once inflammation develops in the cornea, it can cause dilation of surrounding blood vessels, with new blood vessels gradually growing into the cornea, resulting in red eyes. Symptoms may also include eye pain and photophobia. Treatments may include fluconazole eye drops, defibroted calf blood extract eye gel, natamycin eye drops, or other medications, as prescribed by a doctor.
5. Scleritis
Scleritis is often associated with autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis, but may also be triggered by infection or trauma. When inflammation occurs in the scleral tissue, inflammatory stimuli can cause dilation and congestion of scleral blood vessels, leading to red eyes. Symptoms may also include vision loss and ocular congestion. Patients may use medications such as prednisone acetate tablets, dexamethasone tablets, or methotrexate tablets as advised by a physician.
In daily life, maintain a balanced diet rich in foods containing vitamins A, C, and E, such as carrots, oranges, and blueberries, which help support eye health. Avoid using your eyes in excessively bright or dim lighting to minimize eye strain.
