The Secret To Great Laser Vision Correction

Laser Eye Surgery has improved tremendously from the mid-1990s. New generation lasers have improved both the percentage of patients with 20/20 vision after surgery and the quality of vision. The reason behind this has to do with the shape of the cornea (the cornea is the clear front part of the eye which is reshaped by the laser treatment.)

In nature, there are 2 types of cornea shapes, prolate and oblate. Animals with great vision such as eagles and hawks have prolate corneas. Animals with not-so-great vision like frogs have oblate corneas. The human cornea is naturally prolate in shape like that of a hawk, so by nature we have great visual potential.

A prolate cornea is steeper centrally while an oblate cornea is flatter centrally. They look like this:
The Difference between Oblate, Spherical, and Prolate Corneas

 

 

 

 

 

 

 

 

 

(Full disclosure- I found the above image on Google images from a 1999 site of Dr. Carl Wheldon, a brilliant nuclear physicist in the UK. The site is wheldon.talktalk.net. Dr. Wheldon, if you read this, please be flattered that your images were borrowed by a Cornea specialist in California. I mean you no disrespect.)

A big problem with laser eye surgery 10 to 15 years ago was that the quality of vision suffered. Patients would read 20/20 on the chart but complained that it wasn’t very sharp. It turns out the earlier lasers would correct vision but would flatten the cornea to the flatter sub-optimal shape (It would turn hawk eyes into frog eyes.) The laser companies figured this out and developed newer generation lasers that maintain the natural prolate shape of the cornea.

This attention to corneal shape took laser eye surgery to the next level. For example, with older lasers there was a 2% chance that treated eyes would lose a line of vision on the eye chart (for example, their vision with glasses before surgery was 20/20. After surgery their vision could drop to 20/25.) Basically, the vision without glasses was much better, but not as good as it was with glasses or contacts before surgery. The result was good, but it wasn’t as good as it could be.

With wavefront treatments it is very common for patients to tell me that their vision is better after laser eye surgery than it was with glasses or contacts before surgery and the idea of potentially losing vision is foreign to me. In fact, 65% of eyes we do surgery on gain a line of vision. That is, if they were 20/20 with glasses before surgery, I know there is a 65% chance of getting their vision to 20/15 or better without glasses (20/15 is better than 20/20.)

In summary, when getting laser eye surgery go for the best treatment available. Yes, the $500 an eye location might be tempting but the quality of vision will be lacking. Choose eagle eyes, not frog eyes, and you will profoundly change your life for the better.


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