the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve
"The doctor explained that a detached retina was causing her sudden flashes of light and loss of peripheral vision."
The thin layer of cells at the back of the eyeball that contains rods and cones sensitive to light, which trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.
"The doctor explained that his new retinal scan could detect early signs of damage before any vision loss occurred."