The best humans can do is 20/10, with 20/20 being our average.
Any more than that would require our cones to be packed together more tightly to resolve light better.
Apparently a woman named Veronica Seider had a 20/2 visual acuity (according to Guinness) and that she could identify people from 1.5km away, but it seems dubious.
The funny thing is, 30/30 vision means the same thing as 20/20 vision
30/30 would just mean you see at 30 feet at the same clarity that typical eyes see at 30 feet
The best humans can do is 20/10, with 20/20 being our average.
Any more than that would require our cones to be packed together more tightly to resolve light better.
Apparently a woman named Veronica Seider had a 20/2 visual acuity (according to Guinness) and that she could identify people from 1.5km away, but it seems dubious.
https://www.guinnessworldrecords.com/world-records/smallest-visible-object