The retina is the paper-thin tissue that lines the back of the eye and contains the photoreceptor (light sensing) cells (rods and cones) that send visual signals to the brain. Sharp, clear, straight-ahead vision is processed by the macula, which is the central part of the retina. The pit or depression within the macula, called the fovea, provides the greatest visual acuity. The choroid layer contains blood vessels that nourish the retina. Bruch's membraneprovides support to the retina. The retinal pigmented epithelium (RPE) protects and nourishes the retina, removes waste products and prevents new blood vessels from growing into the retina.
Glossary of Terms
Bruch's membrane: Located in the retina between the choroid and the retinal pigmented epithelium (RPE) layer; provides support to the retina and functions as the 'basement' membrane of the RPE layer.
Choroid: Layer of the eye behind the retina; contains blood vessels that nourish the retina.
Cones: The photoreceptor nerve cells present in the macula and concentrated in the fovea (the very center of the macula); enable people to see fine detail and color.
Fovea: The pit or depression at the center of the macula that provides greatest visual acuity.
Macula: The portion of eye at the center of the retina that processes sharp, clear, straight-ahead vision.
Photoreceptors: The light sensing nerve cells (rods and cones) located in the retina.
Retina: The light sensitive layer of tissue that lines the back of the eye.
Retinal Pigmented Epithelium (RPE): A layer of cells that protects and nourishes the retina, removes waste products, prevents new blood vessel growth into the retinal layer and absorbs light not absorbed by the photoreceptor cells; these actions prevent the scattering of the light and enhance clarity of vision.
Rods: Thotoreceptor nerve cells in the eyes that are sensitive to low light levels and are present in the retina, but outside the macula.