According to the faa and 14 cfr part 67, for 1st & 2nd class airman: distance of 20/20 & near 20/40 at 16 inches (if over age 50, at 16 & 32 in) in each eye
with/without lenses and normal fields of vision
For 3rd class, 20/40 at distance and near at 16 inches (any age). If lenses are needed, this will be noted on your faa certificate. There are other stipulations as well. See ecfr.Gpoaccess.Gov.