Distichiasis is -
Congenital anomaly in which an extra row of cilia occupies the position of meibomian gland .Distichiasis is a rare disorder defined as the abnormal growth of lashes from the orifices of the meibomian glands on the posterior lamella of the tarsal plate Ref :Ak khurana 6th edition REF IMG
Abnormal inversion of eyelashes
Abnormal extra row of cilia
Abnormal eversion of eyelashes
Misdirected cilia
Diseases of orbit, Lids and lacrimal apparatus