BLIND SPOT, the place of entry of the optic nerve into the retina, an area insensitive to light with a diameter in man of about one-twelfth of an inch, lying about 1 5 ° from the middle of the yellow spot on the nasal side. In binocular vision the spot is not noticed, because the part of the visual field covered by the blind spot of one eye is covered by a sensitive area in the other. In monocular vision objects which fall entirely within its area are not seen.