Optic disc Interior of posterior half of bulb of left eye. The veins are darker in appearance than the arteries. The terminal portion of the optic nerve and its entrance into the eyeball, in horizontal section. Gray's subject #225 1015 MeSH Optic+Disk The optic disc or optic nerve head is the location where ganglion cell axons exit the eye to form the optic nerve. There are no light sensitive rods or cones to respond to a light stimulus at this point. This causes a break in the visual field called "the blind spot" or the "physiological blind spot". The optic nerve head in a normal human eye carries from 1 to 1.2 million neurons from the eye towards the brain.