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Vision is about light. Here are how some parts of the eye
affect our vision.
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The Stucture of The Eye |
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All light must first pass through the cornea
when it enters the eye.
Light rays then penetrate the lens. Muscles and ligaments
change the shape of the lens to fine-tune the focus of light
onto the retina, the light-sensing
portion of the eye.
In a normal eye, the cornea and lens will refract light in
perfect focus onto the retina. Numerous light-sensitive receptors
in the retina, called rods and cones, give colour and contrast
to our vision.
Most of the light rays are concentrated onto the fovea, a
tiny area on the retina. The fovea is responsible for our
central, sharpest vision. Light stimulates the nerve cells
present there to send “signals” via the optic
nerve to the brain where we perceive images.
The white, outermost layer of the eye, called the sclera,
maintains the shape of the eye. The choroid supplies blood
and nourishment to the tissues in the eye.
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Normal Vision |
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