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biology 0610printed 181 · PDF 181
328 pagesrevision 46933
printed 181 · PDF 181
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The Structure of the Eye
● Eye is found in the bony socket of the skull.
● The eye is filled with a fluid that helps it keep its shape.
● The surface of the eye is always kept moist by a fluid made in the tear
glands. This fluid contains an enzyme called lysozyme which kills bacteria in the eye.
● The retina is at the back of the eye and it is the place where the receptor cells are
present.
● When light falls on the receptor cells on the retina, the cell sends an electrical
impulse through the optic nerve to the brain. The brain uses the impulses from each
receptor cell to build an image.
● There are no receptor cells in the place where the optic nerve leaves the
retina. This is called the blind spot.
● More closely packed the receptor cells, the clearer the image the brain can
produce. The part of the retina where the receptor cells are packed closest together is
called the fovea.