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.
At the optic disc, the 3Â° visual afferents exit the eye and form the optic nerve. The fibers of the optic nerve that originate from ganglion cells in the nasal half of the retina (i.e., the nasal hemiretina) decussate in the optic chiasm to the opposite optic tract (Figure 15.1).etinal Damage: A defect involving only the visual field of one eye indicates possible damage in the retina or optic nerve. If the visual loss is confined to one eye, it is called a monocular visual field defect.