found this when looking for what's the closest two objects we can make out. Apparently there are people who can distinguish 20 arc seconds which would be two black points on white 15 micrometers apart from 10cm away. Which should be almost enough for seeing bacteria.
Or short sighted folks - I have -6 in both eyes and at 10cm things do look awfully sharp. Though more than 10cm away (without glasses/contacts) things are rather fuzzy.
As another nearsighted individual (-4ish), I can attest to this. At short range, without glasses or contacts, I have ridiculous vision, much tighter and sharper than when I have my contacts in, again at very close range. Long range is much less impressive.
Short sightedness is a convergence problem. There's nothing wrong with your fovea, so you still have the sharp vision when using glasses or looking close.