LASIK - What Can It Actually Correct

By: Tara Pingle

LASIK is an acronym for Laser In-Situ Keratomileusis. It has become enormously popular, because it’s:
· Painless
· Quick, and
· Effective.

What is LASIK?

It’s a type of eye surgery in which an extremely precise laser is used to modify the corneal surface so as to remove irregularities that have impaired your vision. The cornea is the front part of the eyeball, the white part around the iris.

· Near-sightedness (myopia)
· Far-sightedness (hyperopia)
· Astigmatism

It does not correct presbyopia, that need for reading glasses that overtakes all of us once we reach the age of 40 or 50. That’s because presbyopia treatments must deal with the stiffening lens and weakening eye muscles, rather than just modifying the corneal surface.

20/20 vision

This term refers to “normal vision” and we’ve all heard the phrase, but what does it mean exactly? It’s a standard of visual acuity which eye doctors have arrived at over the decades, from looking at tens of thousands of pairs of eyes. The “normal” person standing 20 ft. from the eye chart will see all the lines of letters clearly. This is the visual acuity of the majority of people. (In countries that use metric measurements, the distance is 6 meters, so it’s referred to as 6/6 vision.)

Examples

· If you stand 20 ft. from the chart but can only see what a “normal” person can see from 60ft. away, you have 20/60 vision. If the normal person walks away to 100ft., he can’t see the chart as clearly, but if you see it that way standing at 20ft., you have 20/100 vision.

· The higher that second number is, the more myopic you are. If you have 20/200 vision, you’re classified as legally blind in the U.S.

· On the other hand, if the “normal” person has to get up close, say 10ft. from the chart to see what you can see at 20ft., then you have superior 20/10 vision.

Correcting Myopia

When we’re myopic, we have corneas that are too steep. That means the light rays entering our eyes are refracted too sharply, and they come to a focus in front of the retina instead of on it. So we see a blurry image.

LASIK correction

The laser vaporizes tiny amounts of corneal tissue such that the cornea is made less steep. Then the light rays will focus on your retina and you’ll see clearly.

Correcting Hyperopia

In hyperopic vision, the cornea is too flat. So the light rays are refracted too little and come to a focus behind the retina. So again we see a blurry image.

LASIK correction

The laser vaporizes tiny pieces of corneal tissue such that the cornea is made more flat and the light rays can focus on the retina to give sharp vision.

Correcting Astigmatism

Astigmatism consists of small irregularities on the corneal surface, such that vision is uneven and has blurry areas. LASIK correction

The laser vaporizes tiny bits of corneal tissue such that irregularities are smoothed out and light rays can refract evenly towards the retina. That gives you clear eyesight.

Choose your LASIK eye surgeon carefully

Not all of us are good candidates for LASIK treatment. A thorough eye exam must be done to discover whether you’re a good candidate and not all eye surgery facilities want to take the time. Avoid those facilities that advertise low prices and try to process large numbers of patients, giving them little time and inferior service.