Shortsighted

Shortsighted= myopia

Viewed objects fall precisely onto the retina in a normal eye. 

However, often the eye and the cornea continue to grow. 

When the lightbeams are bent too far the imaging will take place in front of the retina. The only lens that can help with farsightedness, is unable to help in this case. Because of this the objects in the distance are blurry. 

One could say that the cornea curves the lightbeams too much. You can prevent them from curving too far by placing a negative glass before the eye. To correct shortsightedness we use minus glasses; thinner in the middle than at the edge. In the case of myopia the burning point is before the retina. The minus (-) glasses lessen the break so that the burning point ends up further back