Corneal histomorphometry of birds from the Brazilian Midwest

The visual structures of birds vary according to their environment, habits, needs of breeding, feeding and predators presence. The cornea is one of the structures in which it is possible to observe clear variations, it is responsible for protecting the inside of the eye, assisting in focusing and refracting the image. Based on the need to know the visual and structural differences between bird species, this work aimed to describe the corneal histomorphometry structures of the following birds: Asio stygius, Crotophaga ani, Pitangus sulphuratus, Turdus rufiventris, Ramphastos toco, Rhea americana, Ara macao and Nyctibius griseus. These are present in the Brazilian Midwest, an area in which the Cerrado is the predominant vegetation. Through the results it was possible to observe that the gross corneal composition is the same in all birds. Although, they differ from each other in the thickness of the central and peripheral regions, even in the total cornea and in its layers, and in number of epithelial lines.