Guide:Reducing normalized

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In general, you only want to reduce 0.25 diopters from a full, 20/20 prescription. The 20/20 standard indicates that you can consistently read the 20 foot or 6 meter line (half or better correct) on the Snellen chart from that distance in reasonably good indoor lighting without active focus. You would do well to wait for the non dominant eye to be at this standard as well, (see ocular dominance). Getting 20/20 once is not necessarily an indication you are ready to reduce, it could just be a good day. Reducing too early leads to unnecessary struggle with excessive blur and eye strain that might slow or even stop your progress. With that consideration, it is a good idea to make sure the 20/20 holds for at least a week if not 2 before reducing.

When introducing a normalized reduction you should perform a "zero diopter reset".

It is a good idea to keep the full correction (your previous normz) handy for night driving; at least for the first stretch of time in your new reduction.

See also

Guide:Reducing differentials

[Guide:How to measure your eyesight]