I’m cursed w/ hard-core nearsightedness. Without corrective lenses the point I can see most clearly is about 5" in front of my nose. At 5" though, I can see VERY clearly. If I just wear one contact, I can actually see very-near objects better w/ my uncorrected eye vs. eye w/ contact lens in.
It just got me to wondering whether I can see better, at 5" distance, than someone w/ “perfect” 20/20 eyesight. I suppose the answer to this would apply to far-sighted individuals too (Those who see perfectly at 40’, but nowhere else.)
Given that features of interest will subtend a larger angle and throw a larger image on the retina at 5" than at 20", the answer is “yes, all other things being equal.” There is more to poor eyesight than the sort of refractive error that can be corrected with lenses.
Also, 20/20 is not “perfect” vision, it’s just the average “best corrected visual acuity” of healthy human eyes.
I can answer from experience. I once worked for an industrial supply company, and part of what we did was identify various pieces of hardware and mechanical parts for replacement.
Very often, when faced with some tiny tiny print on a bolt head or something, I was the only one in the office who could read it without magnification, simply by taking off my glasses and holding it an inch or two from my eye. (I don’t know my actual numbers offhand, but suffice it to say I am VERY nearsighted.)
What Wheelz said is true for me also. Until recently, I just had cataract surgery on my right eye with a lens implant, looking over the top of my glasses was like using a 2 or 3 power magnifier. Now I can only do that with my left eye. That will end in two weeks when the left eye has it’s surgery.
Clear focus on my left eye is at about 5" like his. Now I’ll need to buy magnifying glasses for anything close.
Thirded. I’m the most nearsighted person in my circle of relatives and friends, and I’m the one who gets to read the fine print or dig the miniscule splinter out of a finger, because I’m the one who can see the tiny stuff. Just don’t ask me to read street signs from any distance at all.
I’m very nearsighted and I’ve noticed that wearing my contacts seems to destroy my ability to see very tiny and close up things. I guess I never considered that the contacts are making me see normally and without them I have some sort of superhuman magnifying vision.
For example, I once reared some baby betta fish, which are about the size of a grain of sand when they first hatch. If I took out my contacts, I could see all the little details of them very clearly, but with the contacts in they just looked like tiny blobs.
It’s been suggested that, in ancient times, cameo factories and the like may have preferentially hired nearsighted workers, because they could do “close-up” work without the need for magnifying lenses.
It seems plausible to me, although there is very plausible evidence for the existence of magnifying glasses, and I’ve argued for the use of pinhole viewers for close-up work as well.
The point is, of course, that near-sighted people – as the term itself suggests – can comfortably view objects closer than people with “normal” 20/20 vision, but it comes at the cost of not being able to comfortably view objects farther away. Without glasses, that is.
I used to have an effective unaided focal distance ranging from about 2 inches away to 6 inches away. Now that I’m an old fogey whose lens doesn’t do much adjusting any more, my useful focal distance ranges from about 5 inches away to about 6 inches away.
But within that narrow range I can make out the details of a mosquito’s fingerprint.