Weak-eyesight is a term that generally is used torefer to near-sighted eyes. People who ar

Weak-eyesight is a term that generally is used to

refer to near-sighted eyes. People who are near-sighted can see good at 【M1】______

a short range, but nothing very far away is likely to be a dull 【M2】______

blur.

The term weak eyesight is misled, for in near-sighted eyes 【M3】______

the lens of the eye are actually too strong. The near-sighted lens 【M4】______

is so powerful that it focuses the light coming into the eye too

quick. The image is formed in front of the retina, which 【M5】______

contains the optical nerves. Near-sightedness is common, but its 【M6】______

growth may be gradual; often the blurring of distant objects is so

slight at first that a person may recognize the condition. Near sightedness 【M7】______

is frequently discovered first at school. It is here that

a student first realizes the difficulty of seeing work on the black-board,

whereas another in the class have no trouble reading the 【M8】______

board at all. After discovery, near-sightedness can easy be corrected. 【M9】______

A concave lens is called a "minus" lens because it

increases the power of the lens of itself. 【M10】______

【M1】