What causes a small blister to appear under the eyelash?

Small blisters under the eyelashes may be caused by conjunctivitis, blepharitis, or herpes simplex virus.

1. Conjunctivitis: Poor eye hygiene can allow pathogens to invade the conjunctiva, causing inflammation. This inflammatory response increases eye secretions, leading to such symptoms.

2. Blepharitis: When the meibomian glands are infected by bacteria, viruses, or other pathogens, it can lead to increased glandular secretions, which block the gland openings and result in this condition.

3. Herpes Simplex Virus: If the herpes simplex virus infects the eyelid area, it can also cause small blisters to form under the eyelashes.

In addition, conditions such as meibomian cysts could also be responsible. A definitive diagnosis should be made by a qualified physician at a hospital.