Page 69 - One Million Things: Animal Life - The Incredible Visual Guide

EYES ON STALKS
Thick eyelashes Like many crabs, shore-dwelling ghost crabs have compound eyes
protect eye from
dirt and insects on stalks, giving them an all-around view of their surroundings. If
they spot danger, they disappear instantly into their burrows. The
stalked eyes can also be folded down for protection.

ALL-AROUND VISION INDEPENDENT EYES
Animals—such as rabbits, antelopes, and deer—that graze or A chameleon swivels its two eyes independently of one another
browse on vegetation, have large eyes on the sides of their heads as it looks out for insects. Once prey is sighted, both eyes swivel
that allow them to see to the front, sideways, and behind. This all- forward so the lizard can judge the distance accurately as it
around vision allows them to keep a constant lookout for predators. shoots out a long, sticky tongue to grab its victim.

COMPOUND EYES MIRROR EYES
Crustaceans, such as crabs, and insects, including this dragonfly, A scallop, like a mussel, is a mollusk that has two hinged shells
have compound eyes made up of lots of separate light-detection enclosing its body. When the shells open, they expose two rows
units, each with its own lens for focusing light. The animal’s brain of small eyes. Inside each eye, a mirrorlike surface reflects light
receives signals from all these units to produce a “mosaic” image. onto receptors to form images.

ABOVE AND BELOW WIDELY SEPARATED EYES
The four-eyed fish floats on the surface of fresh water. It has The hammerhead shark has eyes located at the tips of
two eyes, each divided into two parts. The upper half of extensions on each side of its head. Being widely
each eye is adapted for vision in air, so it can see insect prey separated, they give the hammerhead a much bigger visual
on the water’s surface. The lower half sees underwater. range than other sharks as it swims along in search of prey.

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