Cameras can take pictures. Our eyes are like a camera. When we open them， they begin to take pictures. Then they send the pictures to our brain（大腦）. They work like this.

the actual（實(shí)際的） tree

1. Eat the right food. Carrots， liver（肝臟） and milk have a lot of vitamin（維生素） A. They can make your eyes see better.

2. Dont watch a computer or TV for too long. Exercise your eyes.

3. Turn on lights when its getting dark， especially when you are reading.

4. Tell your teacher if you cant see the blackboard clearly.

5. Wear sunglasses and a hat on sunny days.

6. Dont wear other peoples glasses.

* Never throw sand（沙子） or small things at others.

* Never fire（發(fā)射） anything such as toy guns（玩具槍） or paper planes at others.

* Never run with pointy（尖的） things like pencils or scissors in your hands.

1. The giant squid（巨型烏賊） has the largest eyeball（眼球）. Its eyeball can be as large as a watermelon.

2. Dogs cant see the difference between the colors red and green .

3. A chameleons（變色龍的） eyes can look in different directions（方向） at the same time.

4. An ostrichs（鴕鳥的） eye is bigger than its brain.

5. Many hamsters（倉鼠） only blink（眨眼） one eye at a time.