What do we know about shortsight and longsight?
People who wear glasses will tell you that they are short-sighted or long-sighted. Do you know what this means? You are short-sighted if your eye is too long from front to back, or if the curve of your cornea is too steep. This means that the length of your eye and its power to focus don't match up. So, although you can see things close up very clearly, things in the distance are blurred - like the blackboard in a classroom.
Longsight is when you can see things that are far away better than you can see things close up. For example, you might be able to watch the television very clearly, but find it hard to read a book. Long-sight may be caused because the eyeball is too short, so that light i rays are focused behind the retina, and the image is blurry.
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