Laser corrective surgery actually changes the shape of the eye to make the focus point line up as close as possible on the retina. The Retina is at the back of the eye. 

If the focal point is on the retina the you will have good vision. If it's in front of the retina then you are nearsighted "can see close", if the point of focus is behind, you are farsighted, "able to see far away."

Normal Eye

Normal Vision

Occurs when light rays focus exactly on the retina, creating a clear image.

Near Vision Eye

Myopia (Nearsightedness)
Occurs when light focuses before it reaches the retina due to an eyeball which is too long or a cornea with excessive curvature. This causes images which are far away to be blurred while images that are close are seen clearly.

Farsightedness

Hyperopia (Farsightedness)
Occurs when light focuses behind the retina, due to an eyeball which is too short or a cornea with too little curvature.

Blurred and distorted

Astigmatism
This term means that one has multiple points of focus in the eye. This would cause images all images both near and distant to be distorted and blurred.