The human eye is an extraordinary member of the body. The human retina contains 125 million rods and about 6 million cones. This is 70 percent of all the human sensory receptors for touch, taste smell, hearing and sight all put together. That’s how important vision is to our survival. But how does the eye actually see?
Light bouncing off an object goes into the eye, through the cornea and the oval-white lens, which focuses that light on the retina. That’s a thin layer of tissue covering the eye’s back wall (inside the sclera). The retina hosts the eyes’ rods and cones. At the center back is the fovea. Most color-sensing cone cells are here. These cells relay signals that move through the optic nerve to the brain.
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