Aspectos morfofisiológicos del órgano de la visión

Introduction: the eyes are photosensitive organs placed in the bony orbits of the skull. Their function is to transform the light ray into bioelectrical signals. Aim: To describe the morphophysiological aspects of the vision organ. Method: a literature review was performed on articles published from May 2002 to August 2020. The databases Scopus, SciELO, Dialnet, EBSCO, PubMed/Medline were consulted, using the terms "Ophthalmology", "eye", "cellular physiological phenomena", "cranial nerves", for Spanish and English. A total of 20 references were selected. Development: the outline of the vision organ appears at 22 days of embryonic life. The corneal epithelium is a stratified pavement epithelium. The inner region of the choroid, the choroid capillary lamina, consists of a vast network of capillaries and feeds the retina. The decrease in cGMP concentration in the cytosol results in the closure of Na+ channels in the plasma membrane of the rod. THE rhodopsin transformation produces activated opsin, which facilitates the binding of guanosine triphosphate to the α-subunit of transducin. Plasma membrane Na+ channels remain open when rods are not activated by light. Conclusions: the master gene in the development of the vision organ is PAX 6. The sclera has abundant type I collagen fibres in its composition. The choroid is located on the posterior wall of the eyeball, is loosely attached to the fibrous tunic and is highly vascularized.