Conjunctival mucosal overgrowth over cornea-
Pterygium is a degenerative conjunctival fold which encroaches on the cornea in the palpebral area. It must be differentiated from pseudopterygium (an inflammatory fold of conjunctiva encroaching on cornea).Pterygium (L. Pterygion = a wing) is a wing-shaped fold of conjunctiva encroaching upon the cornea from either side within the interpalpebral fissure ref: A K KHURANA OPHTALMOLOGY,E4, Page-80 ref img
Pterygium
Pingecula
Vernal keratoconjunctivitis
Herbe's pit
Conjunctiva