How Does LASIK Work?
LASIK uses a laser to change the shape of the cornea.
In the myopic eye, the image does not reach the back part of the eye (the retina). In the myopic eye the cornea and lens are too curved and focus the image to a point in front of the retina, the image is then seen as a blur.
LASIK involves slightly flattening the cornea which is the curved rounded front surface of the eye; the image is then clearly focused on the retina.
In the hyperopic eye the cornea and lens are too flat and focus the image to point behind the retina; the image is then seen as a blur.
After laser correction with LASIK the cornea is slightly more curved; the image is then clearly focused on the retina.
The result is that the hyperopic patient can see clearly for distance after laser treatment.
In astigmatism, the eye is oval like a football, and not spherical. The image is formed at two different points inside the eye. This means that images of different orientations are focused at different parts of the eye and that the image on the retina is blurred.
In the treatment of astigmatism, irregularities in the shape of the cornea are smoothened to even out the focusing power.