The retina receives visual information and sends that information to your brain. Vision correction procedures can correct nearsightedness.
focuses at a point behind the retina. Some vision correction procedures can be used to correct far-sightedness.
And to help you understand laser vision correction procedures, read the brief descriptions of each of these vision problems.
ELIGIBILITY
LASIK candidates must meet the following requirements.They have to be at least 18 years of age or older and have a stable prescription for glasses or contact lenses for a year prior to the procedure.
 

If you wear corrective lenses, you have one of these vision conditions:

  1. Nearsightedness, also known as myopia;
  2. Farsightedness, also known as hyperopia;
  3. Astigmatism; and
  4. Presbyopia, or what happens after age 40

Far-sightedness, or hyperopia, is when you can see far objects, but you have difficulty seeing objects up close.

This occurs when the cornea is shorter than normal. When the eye is shorter, light enters the eye and

Astigmatism is when you can't see very clear either near or far.

This occurs when there is an irregular curvature of the cornea, which causes two blurred focal points. In many cases, astigmatism can be corrected by laser vision correction.

Presbyopia occurs in everyone sometime after age 40, and causes the need for reading glasses.

Before 40, when you look at a near object, the lens behind the cornea changes shape in order to focus close up. But, as we age, the lens behind the cornea gradually loses its elasticity so that the lens can no longer change shape easily. And this is when reading glasses become necessary. This fact of aging will happen whether you have your vision corrected or not -- and you will eventually need reading glasses -- unless you choose a "monovision correction" which corrects one eye for near vision and the other for distance.

Do You Have Presbyopia?
Do You Have Astigmatism?
Are You Far-Sighted?
Are You Near-Sighted?

Near-sightedness, or myopia, is when you can see near objects, but you have difficulty seeing objects in the distance.

This occurs when the cornea is longer, or more domed, than normal. When the eye is longer, the light enters your eye and focuses at a point in front of the retina.