what is the blind spot of the eye
Blind spot (vision) A blind spot, scotoma, is an obscurity of the visual field. A particular blind spot known as the physiological blind spot, "blind point", or punctum caecum in medical literature, is the place in the visual field that corresponds to the lack of light-detecting photoreceptor cells on the optic disc of the retina where the optic nerve passes through the optic disc.[2] Because there are no cells to detect light on the optic disc, the corresponding part of the field of vision is invisible. Some process in our brains interpolates the blind spot based on surrounding detail and information from the other eye, so we do not normally perceive the blind spot.
Sauron Throughout The Lord of the Rings, "the Eye" (the Red Eye, the Evil Eye, the Lidless Eye, the Great Eye) is the image most often associated with Sauron. Sauron's Orcs bore the symbol of the Eye on their helmets and shields, and referred to him as the "Eye" because he did not allow his name to be written or spoken, according to Aragorn[54] (a notable exception to this rule was his emissary, the Mouth of Sauron). Also, the Lord of the Nazgûl threatened Éowyn with torture before the "Lidless Eye"[55] at the Battle of the Pelennor Fields.