In the human body most important sensory system of vision is eyes. Thought eye is small in size therefore eye is very multifaceted organ. Therefore the retina of eye carry out the first stage of visual perception the next stage of visual perception includes optic never and visual cortex of the brain.

The procedure of working of eyes is as light enter the eye and then pass through the cornea then aqueous humor after that to lens and vitreous humor after going through these stage it ultimately reaches to the retina which is light sensor of the eye.

We see color due to cones called cone pigments this pigments contain color responsive pigments in eye there are three types of color pigments such as Red pigment, Green pigment and Blue-pigment. Therefore every cone has pigment sensitive to the matching color.

If some one have color blindness then it means that cone of eyes are not working properly as due to the failure of cone the incapability of differentiate between colors stops working. Usually individual who suffer color blindness they are only able view red and green color. This problem is .......Read More
http://www.cosmo411.com/blog/2011/05/26/how-human-eyes-work/

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