Light enters the eye through the transparent cornea. The Iris controls the amount of light entering the pupil.As it travels through the lens light is focused on to the retina lining the back of the eye. The retina transforms the image into an ___ impulse. Which travels along the optic nerve to the brain. The spaces either side of the lens is filled with fluid called the vitreous humor. This fluid is under slight pressure and helps the eye keep its shape.
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