What is the condition where the eyelashes roll in and rub against the cornea?

• A. Entropion
• B. Ectropion
• C. Blepharitis
• D. Trichiasis

Answer: (D)

Lashes growing inward toward the eye and rubbing against the cornea is trichiasis. This condition causes mechanical irritation of the corneal surface as the misdirected eyelashes repeatedly contact it, leading to tearing, foreign-body sensation, redness, and potential corneal abrasions or scarring if not treated. It’s different from entropion, where the eyelid margin itself turns inward and lashes may rub as a result; the key feature of entropion is the inward-turning lid margin rather than the lashes themselves curling inward. Ectropion is the opposite, with the lid margin turning outward, and blepharitis is inflammation of the eyelid that can contribute to lash issues but does not describe lashes curling inward toward the eye. Treatments focus on removing or disabling the offending lashes and addressing lid inflammation or malposition.