A total number of 950 Orechromis niloticus (O.niloticus) fish, 500 wild O. uiloticus fish from River Nile at Giza Governorate and 450 cultured niloticus fish from Abbasa farm at Sharkia Governorate were collected at different seasons, to study the incidence of eye lesions, their clinical signs and etiologic agents. The incidence of the parasitic infestation was highest (42.7%) and (39%) followed by Bacterial infection (25.1%) and (14.4%), while the fungal infection was the least (10.4%), (10%) in cultured and wild O. niloticus. Eye lesions were higher in cultured O.niloticus fish (78.2%) than that in wild (63.4%). The eye lesions appeared as uni or bilateral exophthalmae, sink eye and cataract in most parasitic cases, cotton like growth from eye or exophathlmae were lesions accompanied with fungal causes . In bacterial diseases red eye cases were noticed beside all previous signs. The most common parasitic agents isolated from wild and cultured o.niloticus were the metacercariae of the genera clinostomum ( 9% , 20% ) , Diplostomum paracaudm (6% ,15.6% ) , Diplostomum spathaceum (14% ,2.7%) , and sporozoan Myxobolus sp.(10% , 4.4%). The bacterial agent were Aeromonas hydrophila (6%.11.1). Yersenia ruckeri ((4%, 6.4%), Staphylococcus sp. (3%, 4%) and Streptococcus sp. (1.4%, 3.6%) respectively. Two mycotic isolates in wild and culture o.niloticus fish comprised of Saprolegnac sp., (2%,2.2%) and Ichthyophonus hoferi (30%, 8.2%). The prevalence of parasitic infestation in eye affections was highest in summer (63%), (76.2%) and the least at winter (14.8%), (16.3%) in wild and cultured O. niloticus fish.