People who are nearsighted can only see things that are very close to their eyes. Everything else seems blurry. Many people who do a lot of close work, such as writing, reading and sewing, become nearsighted. Then they have to wear glasses in order to see distant objects clearly.
People who are farsighted suffer from just the opposite problem. They see things that are far away, but have difficulty in reading a book unless they hold it at arm’s length. If they want to do a lot of reading, they must get glasses too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism. This, too, can be corrected by glasses. Some people’s eyes become cloudy because of cataracts. Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.
