In sight telepathy, both subjects can actually see each other, and communicate sensible, logical thoughts and instructions, without verbal words. This also seems to be a pattern using light, since the eyes play a big function in sight telepathy (in these cases, the subjects report a strange “warmth” in their eyes when this occurs). While this is the rarest type of telepathy, oddly enough this form is the most common perception by the general public as to what telepathy is all about.
The diagram, by Rene Descartes (1596 – 1650), shows how the eyes were thought to work with the brain several centuries ago. (While this diagram is not fully correct compared to today’s knowledge, I personally like it since suggests more than any other picture, that the eyes are an EXTENSION of the brain). Descartes learned an image entered the eyes and was inverted (which is correct). Then he believed the image was sent along the optic nerve to the brain (partially correct), where inside the brain, the soul viewed the image from the optic nerve endings (while I believe one’s soul views all images, it probably does not happen as pictured here, a tiny man viewing the optic nerve as one would a television set!).
In reality, when an image enters the eye (which is actually LIGHT that has been reflected off of the image), it is converted to electrical impulses BEFORE it is sent to the brain. This is done by the ganglion cells that link the eye with the optic nerve. It is in these cells that we will later focus our attention for obtaining descriptions concerning mental telepathy, and an how this form of communication actually works.