What causes severe pain in the left eyelid?

Generally, pain in the left eyelid may be caused by eye strain, external injury, hordeolum (stye), blepharitis, or eyelid cellulitis. It is recommended to seek medical attention promptly, identify the underlying cause, and receive appropriate treatment under a doctor's guidance. Specific analyses are as follows:

1. Eye strain: Prolonged screen time or staying up late can cause sustained tension in the muscles of the left eyelid, leading to pain accompanied by dryness, grittiness, and aching. To relieve symptoms, look into the distance every 30 minutes during screen use, apply a warm towel compress to the eyes for 10 minutes before bedtime, and ensure 7–8 hours of sleep each night.

2. External injury: Scratching, rubbing, impact, or abrasion from foreign objects can damage local tissues of the left eyelid, causing pain and possibly redness and swelling. Clean the affected area with normal saline, avoid rubbing the eye, and apply erythromycin eye ointment for minor scratches to protect the area and prevent secondary injury.

3. Hordeolum (stye): Blockage of an oil gland in the left eyelid followed by bacterial infection leads to a painful, red, firm nodule. Follow your doctor’s instructions to use medications such as tobramycin eye drops, levofloxacin hydrochloride eye drops, or erythromycin eye ointment. Never squeeze or press the affected area.

4. Blepharitis: Bacterial infection or irritation at the edge of the left eyelid causes pain, itching, and flaking. Clean the eyelid margin daily with normal saline, and apply prescribed medications such as tetracycline hydrocortisone eye ointment, chlortetracycline eye ointment, or sodium sulfacetamide eye drops as directed.

5. Eyelid cellulitis: Infection spreads into the subcutaneous tissue of the left eyelid, causing diffuse redness, swelling, and pain, often accompanied by fever. Oral antibiotics such as cefuroxime axetil tablets, azithromycin dispersible tablets, or minocycline hydrochloride capsules should be taken as prescribed. If an abscess forms, incision and drainage surgery may be required to remove pus.

Maintain good eye hygiene daily: avoid touching eyes with dirty hands and thoroughly remove makeup after wearing it. Eat a light diet, avoid spicy and irritating foods, and consume more fruits and vegetables rich in vitamin A. Wear protective eyewear outdoors to reduce irritation from wind, dust, and other foreign particles.