Every state is different, but in ca, you must be able to see a 20/40 target with each eye in order to pass their screening.
If you don't, they ask you to obtain an eye exam
to document why you can't see 20/40. If the reason is nearsightedness
, your license will have a requirement that you wear corrective lenses while driving. Inability to see 20/40 would translate to about -1.50 or greater.