保护眼睛(Care of Eyes)

　　we see with our eyes. if we have poor eyesight, it will be difficult to see everything clearly. so it's important to take good care of our eyes. it's quite unbelievable that an eye ball is the same size as a table tennis ball. in fact the eye ball is like a kind of mirror. we should do eye exercises every day. we also need to have a rest after a long period of reading.