Abstract

The present study examined histopathological injuries in the structural components of the eye of Noemacheilus tigris fish as a result of exposure, for nine continuous months to green light band at wave lengths 495-570 nm and 550 lux light intensity under 24±1 ºC. Injuries appeared after two weeks of exposure. They were pyknosis of some corneal histological components (surface epithelium, annular ligament and descemet membrane), iris bleeding and hyperplasia of iris guanophores cells and the lens showed pyknosis of epithelial cells and central portion. After one month of exposure the damage increased and was corneal epithelium damage, annular ligament necrosis, iris bleeding, iris guanophores hyperplasia and signals of lens cataract. After two months, the injuries continued in the components of cornea, iris, lens; necrosis of central and peripheral retina appeared (edema and detachment of peripheral retina, disruption of pigment epithelial cells, rods and cons), and some of the choroidal vessels disrupted and necrosis of choroid gland seen. Injuries in all eye components increased after nine months of exposure the corneal injures were deterioration of epithelium, swelling and necrosis of stroma, iris stroma necrosis and clusters of melanocytes seen. The lens fibers damaged and the lens appeared as comma shape. In the central and peripheral retina semi complete damage of the pigment epithelial cells and photoreceptors and bleeding appeared. The outer and inner nuclear layers reduced. Most of the choroid components damaged and hyperplasia of argenteum layer revealed.