There are three theories for the explanation of<unk> . The first states that after damage to area V1, other branches of the optic nerve deliver visual information to the superior colliculus, pulvinar and several other areas, including parts of the cerebral cortex. In turn, these areas might then control the<unk>  responses. Another explanation for the phenomenon of<unk>  is that even though the majority of a person's visual cortex may be damaged, tiny islands of functioning tissue remain. These islands aren't large enough to provide conscious perception, but nevertheless enough for some unconscious visual perception. A third theory is that the information required to determine the distance to and velocity of an object in object space is determined by the lateral geniculate nucleus (LGN) before the information is projected to the visual cortex. In a normal subject, these signals are used to merge the information from the eyes into a three-dimensional representation (which includes the position and velocity of individual objects relative to the organism), extract a vergence signal to benefit the precision (previously auxiliary) optical system, and extract a focus control signal for the lenses of the eyes. The stereoscopic information is attached to the object information passed to the visual cortex. More recently, with the demonstration of a direct input from the LGN to area V5 (MT), which delivers signals from fast moving stimuli at latencies of about 30 ms, another explanation has emerged. This one proposes that the delivery of these signals is sufficient to arouse a conscious experience of fast visual motion, without implying that it is V5 alone that is responsible, since once signals reach V5, they may be propagated to other areas of the brain. The latter account would seem to exclude the possibility that signals are "pre-processed" by V1 or "post-processed" by it (through return connections from V5 back to V1), as has been suggested. The pulvinar nucleus of the thalamus also sends direct, V1 by-passing, signals to V5 but their precise role in generating a conscious visual experience of motion has not yet been determined. Evidence of<unk>  can be indirectly observed in children as young as two months, although there is difficulty in determining the type in a patient who is not old enough to answer questions.
Blindsight
Underwater vision
Sharsheret 
Far-sightedness
Tunnel vision
Hot flash
Itch
Mesopic vision