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Chapter One
THE CHESHIRE CAT AND OTHER
EYE-POPPING EXPLORATIONS OF
HOW WE SEE THE WORLD
How do you see the world around you? You open your eyes and there it
is: your room, your desk, the pictures on the walls, the trees outside your
window.
When you take a look at the world, here's what's happening: Light is bouncing
off the pictures, the trees, and all the things out there in the world. Some
of that light gets into your eye. This light shines through the cornea, the
tough, clear covering over the front of your eye, and then through the pupil,
the dark hole in the center of your iris, the colored part of your eye. Your eye's
lens focuses this light to make an image on your retina, a thin layer of light-sensitive
cells that lines the back of your eyeball. The light-sensitive cells of
the retina signal the brain, and the brain creates a mental image. Finally, you
see the world "out there."
People have compared the eye to a film-loaded camera-and for good reason.
Both your eye and a camera have adjustable openings t ... read full excerpt from: The Exploratorium Science Snackbook: Cook Up Over 100 Hands-On Science Exhibits from Everyday Materials ebook
