I have 20/30 vision in one eye, 20/50 in the other. With glasses, I get 20/20 in both. What are the visual acuity requirements for a PPL? Presumably (hopefully?) someone with my visual acuity can't fly without glasses? (I definitely wouldn't even drive a car, let alone fly a plane, without glasses, even if it wasn't legally required. I could probably see the instruments in a plane fine, and I could see outside well enough to avoid hitting another plane, but I would probably have a hard time finding a runway to land on.)
If you're correctable to 20/20, then you'll pass the vision test just fine (unless there are other issues beyond what you've described). If you require glasses in order to pass, your medical certificate will have a note to the effect that you have to wear (or, "have available" in many cases) glasses while flying; that's very common, especially among pilots older than about 45, which is when presbyopia typically starts to set in.
Even 20/20 isn't strictly necessary; if you have 20/25 distant vision and good near vision, there's no need for glasses. The flight surgeon can tell you the exact limits, but since you're correctable to 20/20, that answers the specific question for your case.
$\begingroup$ Thank you! I do have astigmatism, but it's also correctable with glasses. $\endgroup$– SomeoneOct 3, 2022 at 18:16
1$\begingroup$ @Someone I can imagine astigmatism to be overwhelming for commercial pilots (nightflying near busy airports involves all kinds of lights), but as small-time flyer you should be fine. $\endgroup$– MastOct 4, 2022 at 16:08
$\begingroup$ @Mast I probably wouldn't fly at night, considering that it's hard to drive at night (although I can do it). $\endgroup$– SomeoneOct 4, 2022 at 18:13
The FAA has pretty straight-forward rules for vision acuity for 3rd class medical certificates, which (unless you're flying under Basic Med) is required to exercise private pilot privileges:
Near Vision: 20/40 or better in each eye separately (Snellen equivalent), with or without correction, as measured at 16 inches.
Distant Vision: 20/40 or better in each eye separately, with or without correction.
The old saying is that if you can walk to the doctor's office unaided and read the name written on the office door, you'll probably pass the third class medical exam.