Trichiasis is misalignment of eyelashes, which rub against the eyeball, in a person who does not have entropion.
Trichiasis develops most commonly some time after chronic blepharitis (inflammation of the edges of the eyelids) or injury or damage to the eyelid or conjunctiva. Some people are born with an extra eyelid skinfold (epiblepharon) that causes the eyelashes to grow straight up into the eye or with an extra row of eyelashes (distichiasis).
Trichiasis differs from entropion (a condition in which the eyelid is turned inward) in that the eyelid position is normal.
In people with trichiasis, an eye doctor can remove the eyelashes with forceps. If eyelashes grow back, other methods can be used to remove them, such as electrolysis (use of heat and electrical current to destroy the hair follicle) or cryosurgery (use of extreme cold to destroy the hair follicle).