How the eye works?

In order to understand how the Excimer laser works is important to know how the eye functions.

The eye works the same way as a camera. Light rays are directed through the cornea and the lens and are projected onto the retina at the back of the eye. The image is then transmitted to the brain. The brain interprets what we see.

The normal eye


If you are shortsighted, your eyes are myopic and distant objects appear blurred. Laser surgery can correct this.


If you are longsighted, your eyes are hypermetropic and objects close to you appear blurred. Laser surgery can correct this.


If you have an astigmatic eye or eyes, your focus on the horizontal plane at one point is different to your focus on the vertical plane - which means you could be shortsighted on one plane but long sighted on the other. Laser surgery can correct this.


If you are getting older and your ability to read is failing - but your distance vision is normal, you have presbyopia (difficulty focusing close-up). The only way one can prevent wearing glasses or contact lenses with presbyopia is to make one eye shortsighted for reading. This means that one eye is used for distance and the other for reading. This is called monovision.