Definition of demurrer 1: a response in a court proceeding in which the defendant does not dispute the truth of the allegation but claims it is not sufficient grounds to justify legal action 2: objection
blind spot. The beginning of the optic nerve in the retina is called the optic nerve head or optic disc. Since there are no photoreceptors (cones and rods) in the optic nerve head, this area of the retina cannot respond to light stimulation.As a result, it is known as the blind spot, and everybody has one in each eye.he beginning of the optic nerve in the retina is called the optic nerve head or optic disc. Since there are no photoreceptors (cones and rods) in the optic nerve head, this area of the retina cannot respond to light stimulation.
Retinal nerve fibers exit the eye through the optic nerve, located nasally and on the same plane as the anatomical center of the retina. There is no retinal tissue overlying the optic nerve head. The optic nerve head or optic disc is oval in shape and measures approximately 1.75 mm. vertically and 1.5 mm horizontally.