How is the 12mm distance between the spectacles and the cornea compensated for during a pre-LAISK evaluation?

If my manifest myopia is of -5D, would be the final LASIK correction be the same (-5D) or more in order to compensate for the 12mm distance between the spectacles and the cornea? Is there a conversion factor that helps derive the degree of LASIK ablation from the pre-LASIK manifest myopic power?

Doctor Answers 1

Lasik calculations

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Lasik correction is achieved near the cornea surface, just as with contact lenses. Measurements obtained with spectacles, which are 12 millimeters from the corneal surface, are mathematically converted to the appropriate measurements at the corneal surface, which can be around an 8% difference. 

Los Angeles Ophthalmologist
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