How a laser can improve/correct someone’s eyesight.


How does laser eye surgery actually work? Which part of the eye are they working on and how is a laser the tool of choice?

In: Technology

I’ve had lasik. Basically removes the top (bad) layer of your eye so you can see clearly again.

Your eye works kind of like a camera. It’s got a lens system that focuses light onto the retina, the part of the eye that senses light. If the lens system is out of whack, the light doesn’t focus right, and your eyesight is blurry.

One way to correct this is to put another lens in front of the whole thing. That’s glasses or contacts.

Another way to fix it is to change the lens system of the eye itself. The shape of a lens is very important in determining how it will focus light. Change the shape, change how it focuses light.

With laser eye surgery, they don’t change the lens itself. They change a layer of tissue in front of the lens, called the cornea. To the best of my knowledge, the laser very precisely burns away parts of the cornea to change its shape.

Here’s a link with lots of information:

You may be most interested in the section called “During the procedure”.

The cornea is the outer layer of your eye. It focuses light on the lens, which then projects the light onto the retina, which actually transmits the image to your eye. Muscles in your eye can squeeze and stretch the lens to adjust the focus.

Laser eye surgery (typically) changes the shape of the cornea to adjust the initial focusing of the light that falls on the lens. There are other types of surgery that don’t use a laser, but making a complex adjustment to the cornea can be done easily and quickly with a computer controlled laser.

Laser is used to cut the cornea of your eye. Before lasers, a really really really good surgeon would do it with a steady hand and a ultra sharp scalpel.

Lasers are used in combination with stabilization machinery to be more precise and reduce error. But it’s really same principle as doctor using a scalpel.