The cornea and lens perform most of the light focusing so that the eye is able to see an image clearly. The cornea does most of this focusing task. When the eye is longer or shorter than usual , the image is not focused clearly. In laser refractive surgery , we re-shape the cornea by removing a portion of tissue. Once appropriately reshaped, the eye will now be able to focus light clearly without the need of spectacles. The amount of tissue removed is the same across all procedures. The method of the tissue removal is what differs from procedure to procedure