HOW WE SEE

As light travels in a straight line, our eyes like a camera, must be pointed at the subject. The camera is very similar to the eye and as such is the the only machine modeled on a sense organ. However, unlike the camera, the eye takes two pictures  simultaneously, one in black and white and the other in colour. Special cells in the retina, called rods register black and white only - these are very sensitive to light detecting light as low as 100- billionth of a watt. Other cells in the retina called cones are affected by colour and and are concentrated around the fovea, the area where the light falls when the eye is focused. Where the optic nerve leaves the retina and sends the information to the brain for processing, there is neither cones nor rods and this causes a blind spot where no information is recorded.

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We see the world with more information on the horizontal than the vertical, and this vision falls off towards the perimeter where objects are less sharp and defined.

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