Here are just a few (but, again, not all) of the possibilities that you are likely to run into:

Free-form lens with no individualized optimization (e.g., the original Definity lens)

Free-form lens with a prescription "tweak" at the distance or near reference points

Free-form lens with full prescription optimization over the entire lens based on average parameters, with or without the "tweak" at the reference points

Free-form lens with full prescription optimization over the entire lens based on specified parameters (requires additional measurements)

Free-form lens with design customization (i.e., the viewing zone configuration, periphery design, and/or corridor length is modified)

Free-form lens with design customization and full prescription optimization, with or without the "tweak" at the reference points

Note that any lens with a prescription "tweak" at the distance and/or near reference points will require a Compensated Rx in order to verify the original prescription.

Darryl Meister/Optiboard

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