Trichiasis refers to upper or lower eyelid lashes that are misdirected. Typically, the eyelashes are misdirected towards the eye causing the lashes to touch the conjunctiva or cornea. This can lead to symptoms of irritation and corneal changes that can affect vision. The eyelashes can be epilated with forceps or can be permanently removed with more aggressive measures.
In some cases, trichiasis is caused by scarring of the eyelid. These instances require more aggressive surgical correction.