Overcorrection

[DryEye]

What is considered overcorrection?
Anything past 20/0 when reading the chart in a doctors office?
Thanks

[LasikExpert]

When the correction is greater than the target, it is overcorrection. If the final correction is less than the target, it is undercorrection. It's always the target that counts, and the target is not always plano (no refractive error).

If patient is 5.00 diopters myopic (nearsighted, shortsighted), the target is -1.50 for monovision correction, and the final correction is plano, then the patient realized a 1.50 diopter overcorrection.

If the same patient's target is plano and the final correction is -1.50, then the patient is undercorrected 1.50 diopters. If the same patient has a target of plano and the final outcome is 1.50 diopters hyperopic (farsighted, longsighted), then the patient is 1.50 diopters overcorrected into hyperopia.

If a patient is 3.00 diopters hyperopic and the final correction is -1.50, then the patient would have realized a 1.50 diopter overcorrection into myopia.