There are many commonly held beliefs about eyeglasses and eyesight that are not proven facts. For instance, some people believe that wearing glasses too soon weakens the eyes. But there is no evidence to show that the structure of eyes is changed by wearing glasses at a young age. Wearing the wrong glasses, however, can prove harmful. Studies show that for adult there is no danger, but children can develop loss of vision if they have the wrong glasses.

　　We have all heard some of the common myths about how eyesight get bad. Most people believe that reading in dim light causes poor eyesight, but that is unique. Too little light makes the eyes work harder, so they do get tired and strained. Eyestrain also results from reading a lot, reading in bet, and watching too much television. But although eyestrain may cause some pain or headaches, it does not permanently damage eyesight.

　　Another myth about eyes is that they can be replaced, or transferred from on person to another. There are close to on million verve fibers that connect the eyeball to brain, and as if yet it is impossible to attach them all in a new person. Only certain parts of the eye--the cornea and the retina--can be replaced. But if we keep clearing up the myths and leaning more about the eyes, someday a full transplant maybe possible!

One cause of eyestrain mentioned in the passage is ____.（　　）

• A.wearing contact lenses too long
• B.going to the movies
• C.reading a lot
• D.not visiting your eye doctor