Reminder, if you're in the US, the FTC says your eye doctor
must give you your prescription after your exam. If a doctor refuses to do so, they can face legal action and penalties.
https://www.consumer.ftc.gov/blog/2016/05/buying-prescriptio...
That said, I don't think the FTC stipulates what information must appear on the prescription. Many docs leave off your PD (pupillary distance), which is a necessary measurement if you're buying online. Fortunately, there are a variety of easy ways to take this measurement yourself after the exam, although if you're really concerned about precision, you'll want the doctor's measurement.
And by the way, it should go without saying, but I'll say it anyway. Although the quality of eyewear available online can be comparable to what you'd get in store ... please don't think an online eye exam is an acceptable substitute for visiting an ophthalmologist in person and getting a comprehensive eye exam!
https://www.consumer.ftc.gov/blog/2016/05/buying-prescriptio...
That said, I don't think the FTC stipulates what information must appear on the prescription. Many docs leave off your PD (pupillary distance), which is a necessary measurement if you're buying online. Fortunately, there are a variety of easy ways to take this measurement yourself after the exam, although if you're really concerned about precision, you'll want the doctor's measurement.
And by the way, it should go without saying, but I'll say it anyway. Although the quality of eyewear available online can be comparable to what you'd get in store ... please don't think an online eye exam is an acceptable substitute for visiting an ophthalmologist in person and getting a comprehensive eye exam!