Judged: two independent readers; copy check clear.
optic disk
optic disk The optic disk is the visible part of the optic nerve at the back of the eye, as seen during an eye examination of the fundus.
The optic disk is the visible part of the optic nerve at the back of the eye, as seen during an eye examination of the fundus. It is the point where the axons of retinal ganglion cells come together and enter the optic nerve.