purpose of choroid
Function. The choroid lies between the retina and the sclera. It is the posterior portion of the uveal tract and is a high-flow vascular tissue that provides nourishment for the back of the eye.In addition, there are pigment cells within the choroid that absorb stray light and so it helps to lessen glare within the eye.he choroid is an extremely vascular layer, with a plexus of blood vessels that reduce in size from its outermost to innermost borders. Blood passes into the choroid from arteries that connect behind the eye around the insertion of the optic nerve.