Distichiasis means

Distichiasis: Congenital distichiasis: It is a rare anomaly in which an extra row of cilia occupies the position of Meibomian glands which open into their follicles as ordinary sebaceous glands. These cilia are usually directed backwards and when rubbing the cornea, should be electroepilated or cryoepilated. Acquired distichiasis (metaplastic lashes): occurs when due to metaplasia and differentiation, the meibomian glands are transformed into hair follicles. The most impoant cause is late stage of cicatrizing conjunctivitis associated with chemical injury, Stevens-Johnson syndrome and ocular cicatricial pemphigoid. Ref:- A K KHURANA; pg num:-342,343