rétine

The rétine, or retina in English, is the light-sensitive tissue lining the back of the eye. It converts incoming light into neural signals that are processed by the brain to produce vision. The retina is part of the central nervous system and is organized into multiple cellular layers containing photoreceptors, interneurons, and glial support cells.

The primary photoreceptors are rods and cones. Rods are highly light-sensitive and enable vision in dim conditions, while cones detect color and provide sharp, detailed vision, with the fovea—an area of high cone density—supporting the highest acuity. Photoreceptors connect to bipolar and horizontal cells, which relay signals to ganglion cells. The axons of ganglion cells form the optic nerve. The retina also contains the retinal pigment epithelium, essential for photoreceptor health, and Müller glial cells that maintain retinal homeostasis.

Blood supply to the retina is layered: the inner retina receives nourishment from the central retinal artery, while the outer retina is nourished mainly by the choroid.

Clinically, the retina is central to several eye diseases, including retinal detachment, diabetic retinopathy, and age-related macular degeneration, all of which can threaten vision. Diagnostic tools commonly used are optical coherence tomography (OCT), fundus photography, and electroretinography (ERG). Early detection and treatment are important for preserving visual function.