What is the definition or description of: detached retina?

Retinal detachment. The retina is the light sensitive layer in the back of the eye that transmits images to the brain via the optic nerves to create vision. If a hole or tear develops in the retina, eye fluids can separate the retina from underlying layer (choroid) . The most common cause of retinal holes or tears is traction from the vitreous, the clear gel that fils the inside of the eye and injuries.
Retina... ...Comes off the eyeball wall, like wallpaper off a wall.