Diopters. We stopped calling glasses “prescriptions” a while back, since we don’t believe a reasonable educated individual needs a so-called professional to tell them which piece of clear, curved piece of plastic to buy. (or conversely, keep you from making your own diopter choices)
If anything, we believe that most of the mainstream will give you more diopters than you need, causing progressive myopia and all sorts of long term risky side effects. We feel strongly about education you on the subject of testing your own refraction, of making your own diopter choices. Glasses are far less dangerous than lots of over-the-counter drugs! Read this section for all things related to diopters, learn about the fascinating world of bending light (to your will).