Trichiasis Trichiasis Trichiasis is a medical term for ingrown hair in the eyelashes. This can be caused by infection, inflammation, autoimmune conditions, and trauma such as burns or eyelid injury. Standard treatment involves destruction of the affected eyelashes with electrology, specialized laser, or surgery. External link Overview by Ron. W. Pelton, MD, PhD <!– –> Want to add or edit information? Send us an Email to register as an editor or sign up for a Professional Membership!