Theoratical limit of human visual accuracy? How well is best possible with 100% perfect eyes

I did a search on google but couldnt find much. I did find that
everyone agrees its 20/10, almost everyone agrees its 20/8, some agree
its 20/5 and a few believe it can be even better! I know one guy who
claims to be able to see the 20/10 line easy from 25 feet and even from
a little more than 30 feet he can still see it, although he proclaimed
it begins to lose shape around 30 feet. I told him hes definately
better than 20/10 and probably 20/6 to 20/8. He also says he can
discern 100fps and movies are a slideshow to him! He can see 240
degrees whereas normal people see 180-210 degrees! His night vision is
almost as good as an owls too! We discussed his uber amazing vision and
he says hes one of the best but goes on to add theres people that may
see a little better than me, like 20/5 or even 20/4 and he knows one
guy who claims hes 20/5!

Theres a website where you can print a snellen chart that goes down to
20/4 so perhaps theres 5-10 guys/humans in the world who can see 20/4?
I read that its commonly accepted hawks see 20/5 and its 20/2 for
eagles! This in comparsion to 20/20 for a plano human! Some see better
than 20/20, others worse. High order aberrations are largely to blame
for this because I read that a healthy retina is capable of at least
20/8! Lots of people arent correctable to 20/20 due to high order
aberrations(even compenstating for spectacle minification perhaps have
them wear contacts) 20/20 is often referred to as perfect vision
because this means nothing is wrong with your eyes and you also are
plano. I wonder what 20/20 vision looks like, never mind 20/15, 20/10
or better! Is everything just very 3-D and really stands out? Are
colors and contrast vivid? Do you see details no one else does like the
leaf here:

http://www.ibrium.se/desktop_picts/jpg/Ducouret/Leaf(915x629).jpg

from a distance? or the bark of a tree like that from half a mile?

http://www.prairiepoint.net/journal/images/P7260023.jpg

 

"Begins to lose shape? This guy is delusional."

He begs to differ and would challenge anyone who doesnt believe him. Be
warned its not for the faint of heart, he told me several people have
actually fainted when he demostrated how good his vision was! One
optometrist in his handwritting wrote tiny letters and he read it
across the room then bam he was laying on the floor, had fainted! One
optometrist literally threw him out of the room after he rapidly and
effortlessly read the 20/10 line! Said he had godly vision or something
and that it was a waste of his time. As for losing shape, anyone will
note that if you stand far enough letters begin to look like
............. instead of l e t t e r s.

"A nut case. Maybe with a huge exotropia, which would be the only
possible explanation for the 240 degrees, and is plainly lying about
the
cff of 100."

I think his 240 degrees is the threshold where your aware of some
presence. You could walk diagonally behind me and I will be aware
something crept behind me but I wont know what. I did have a pharphiel
vision test and they said 200 degrees is when I was aware of the moving
object but it had to be like 90 degrees before I could read the
letter(s) on the card. As for seeing 100fps, ive seen several people
claim this. They cant watch TV or movies without getting a headache as
its a series of still frames!


"Try searching on "diffraction limits" on visual acuity. Physics wins,
B.S.ers lose."

I did and already stated that theres some disagreement on this. One
researcher claims humans could potentionally see 20/2.5 in theory which
is what many eagles normally see but goes on to say 20/15 to 20/12 is
the "typical" limit due to high order aberrations. He goes on to
explain the limits of the retina and the spacing of the cones and the
phenomeon of spatal antialising. In all, he believes 20/2.5 if your
RMS(root mean square) of aberrations is absolutely zero and your pupils
are huge. Huge pupils with aberrations results in more blur but in the
absense of aberrations, it actually results in clearer vision!

Any optometrists have any comments on this or anything reguarding the
limits of vision?

 

I was going to reply to this, but I realized that this isn't
sci.med.humor.

 

Ok, Ok. So maybe he's a troll, or just having fun. Plonk.

 

"In the US, TV is 30 fps, and yes there are some who can appreciate 30
fps,
mostly with their peripheral vision. Still, it's a long way from there
to
100 fps."

TV has motion blur, movies and games dont so he sees still frames much
easier.

"Huge pupils make it much harder to reduce aberrations, if that
matters."

Yes because large pupils cover more aberrations and for most people,
they see best with pinhole pupils, especially if they have a refractive
error. However for those without aberrations they actually see better
with dilated pupils, hence this guy with hyper vision sees almost as
good as an owl at night! He can see his toes in pitch blackness!


"Whatever you think, the best real-life outcomes with wavefront PRK
correction still come up around 20/10 on the Snellen chart"


He never got surgury and his vision is uncorrected! If you can get
20/10 with wavefront PRK you were seeing that good with corrective
lenses in the first place. In fact many people corrected to 20/10 dont
get 20/10 after laser surgury, sometimes not even with correction
anymore. You need nearly perfect, nearly aberration free eyes to see
20/10 and laser surgury induces aberrations. I would not reccomend
surgury to anyone correctable to 20/10, its too good a BCVA to risk.


"which is also
about the best we can get with good gas perm contacts or glasses."

20/10 is much more unusual with glasses because of minification and RGP
doesnt minify plus provides the crispest vision. I have been told I
"should" be getting 20/20 with RGP. Right now I get 20/30 with -5
glasses. -5 glasses make the 20/25 line too small to accurately see.


""Better
than normal," or "hyperacuity," is still unusual."

No kidding but I seem to see a fair amount of 20/15 vision with or
without correction. I guess 20/10 is where hyperacurity starts.


Snellen accuracy is something we are all familiar with. I didnt even
know vernier accuracy till I looked it up. Also I could score well on
the vernier but not well on the snellen. Optometrists use the snellen
as a benchmark of vision accuracy and its the most popular test


"I was going to reply to this, but I realized that this isn't
sci.med.humor."

sir, I am not joking here. I asked a serious question.


"Ok, Ok. So maybe he's a troll, or just having fun."


Not a nice thing to say or assume about me, sir. I know your a good
optometrist and I respect you so we must have a misunderstanding there.
I am interested in this discussion and knowing about the limits of
human vision.

 

Sorry, but you seem very, very gullible at the least. You need to learn
to be a little more skeptical, especially of spectacular single case
claims by anyone, which are known in the science field as testamonials
and in the statistics field as n=1 self studies. In law your post is
called hearsay and is not allowed in court for a multitude of good reasons.

This group is called SCI.med.vision because we try to keep it
scientific. If you want to be a scientist, get this guy to submit to a
real evaluation of his self-claimed super vision by a neutral scientist
using proper technique. It would still be n=1 but might qualify as a
case report rather than a simple hearsay testamonial.

w.stacy, o.d.

 

"What if they show a movie on TV? "

Hes referring movies as the ones you see in theaters. Its a series of
still frames to him so he almost never goes to theaters. TVs are more
tolerable due to motion blur but still annoys him but he deals with it.



"Oh. I thought the purpose of wavefront surgery was to reduce
aberrations."

technicially it does vs. standard lasik. wavefront induces less
aberrations. In highly aberrated eyes, wavefront offers some relief but
in virgin eyes youll get induced aberrations. I dont think ive seen a
single person really end up 20/10 after lasik. Inflated results dont
count. Is guessing allowed? The standard is to get the majority of
letters right, more than 2/3 of said line. I read that doctors/surgeons
like to inflate results to make their stats look good. I speak from
experience when I went to one of those for an eye exam, I read/guessed
maybe half of the 20/25 line and could see none of the 20/20 but he
said guess so I did and got one right then he wrote down im 20/20 to
20/25 with a -5 lense on the phororaptor.


"Most of the -500 myopes I see can get 20/20 or better with their
glasses.
Minification may not explain your problem."

see above. That technician considered me a partial 20/20. True 20/20 is
alot less common, especially with the minification of a -5 lense. No
one in my family is really correctable to 20/20. My mom can see 20/30
and some of the 20/25 with contacts and only 20/30 with her -7.5
glasses. My fathers a +6 and yet hes only correctable to 20/25 but he
may be able to see/guess some of the 20/20. My brother had an eye exam
and despite he being a -1(not much minification) he could not see all
of the 20/20. I think he got 3 out of 5. My sister has about 80-90%
accuracy of 20/20 with contacts which is good enough to count, Ill give
her credit for 20/20. My sister's friend has the best vision ive seen.
She told me her optometrist recorded her as 20/10 but she isnt. I
watched her read a standard snellen chart and she did get all of the
20/15 line and 80% of the 20/13 line and like 2 of the 20/10 line. Hey
if you blindfold me and let me guess the 20/10 line I could get lucky
and get a few right. Means nothing. I could also guess where the dice
will land. I do give her credit for 20/13. At one store I told her to
stand back as far till she can just barely make out the sign. I then
stood back myself. I was amazed to see that she was standing back twice
as far, maybe a bit more than I was! This would make me worse than
20/25, perhaps 20/28 with -5 and I could probably get about 80% of the
20/25 line with proper contacts since they dont minify so the 20/25
line will be a little bigger. So im only one line away from perfect
20/20 BCVA without minification, minification is an artifical limit,
many high myopes see 20/25 with glasses but the 20/25 they see is about
the same size as the 20/20 line with contacts. Having a few extra high
order aberrations or a little irregular astigmastim can easily mean one
line difference. How do you explain some being 20/15 BCVA while others
20/25? Obviously someone whos only a -1 is much more likley to see
20/20 than someone whos a -5 and especially higher. With contacts its
all equal(20/20) as long as the retina is fine and you dont have a
whole lot of aberrations.
I think optometrists are being quite generous reguarding BCVA. I
remember one time I looked into a vision screener with my full power
glasses and I read 20/40 and half of the 20/30 in the left and my worse
right eye was struggling to see 20/40. I can definately tell the right
eye isnt as good as the left when looking about the store and closing
one eye at a time. I consider myself 20/30 with -5 glasses to put it
simply.


"You need to learn
to be a little more skeptical, especially of spectacular single case
claims by anyone"


I am indeed skeptical but he insists hes telling the truth. I did a
search online and read that the retina is indeed possible of better
than 20/10 so while hes a very rare case of hypervision, its
potentioanlly true. Hes just got very special, aberration free eyes!


"law your post is called hearsay"


whatever happened to freedom of speech? This is not a trial so no one
is under oath of perjury. Besides if this is misinformation, its his
fault, not mine!


"If you want to be a scientist, get this guy to submit to a
real evaluation of his self-claimed super vision by a neutral scientist

using proper technique."


I told him, he doesnt seem to care. Is there anything good in it for
him? If there is, I will point it out and get him to submit to eye
exams by optometrists and scientists. William, what was the best visual
accuracy youve personally seen? How rare is 20/10 even?

 

In a court setting, it's not allowed because of the certainty that the
facts will be distorted on the 2nd hand retelling. Free speech does not
apply when the judge says "sustained" to the objection of hearsay. The
witness must shut up.

If it's misinformation IT IS YOUR FAULT for spreading the garbage here
as if it were fact. Nobody's under oath, but I'm telling you to shut up
with the hearsay and testamonials. It's my freedom of speech.

Of course he doesn't. Nobody who exaggerates his physical prowess wants
to submit to independent examination. The fact is, the ones who
exaggerate are often the ones with less than average prowess.

I see 20/10 regularly. I don't routinely test below 20/10 because my
exam rooms are not set up for it. There's a good reason standard eye
exam rooms are not set up to test for better than 20/10. Can you guess
what that is?

w.stacy, o.d.

 

William Stacy wrote: (what looks like an empty post, sorry; here's what
I intended to post in response to aceman):

In a court setting, it's not allowed because of the certainty that the
facts will be distorted on the 2nd hand retelling. Free speech does not
apply when the judge says "sustained" to the objection of hearsay. The
witness must shut up.

If it's misinformation IT IS YOUR FAULT for spreading the garbage here
as if it were fact. Nobody's under oath, but I'm telling you to shut up
with the hearsay and testamonials. It's my freedom of speech.

Of course he doesn't. Nobody who exaggerates his physical prowess wants
to submit to independent examination. The fact is, the ones who
exaggerate are often the ones with less than average prowess.

I see 20/10 regularly. I don't routinely test below 20/10 because my
exam rooms are not set up for it. There's a good reason standard eye
exam rooms are not set up to test for better than 20/10. Can you guess
what that is?

w.stacy, o.d.

 

My eldest brother drove me to an ophthalmologist appointment once.

While I was reading the eye chart, Allen stood over my left
shoulder--maybe two or three feet further from the wall than I.

After reading the 20/10 line, he--literally--read the patent number on
the bottom of the chart.

I love my brother, but--needless to say--I don't /like/ him very much,
and I don't get rides to the eye doc from him anymore....

 

He covered that, remember? The first guy swooned and the
second threw him out.

-Quick

 

A question is fine. You posted about somebody having 20/4 vision.

 

"Of course he doesn't. Nobody who exaggerates his physical prowess
wants
to submit to independent examination. The fact is, the ones who
exaggerate are often the ones with less than average prowess."


Good point. However hes probably still 20/10 but exaggerates how well
he sees and all that. is 20/10 something to brag? I would imagine it
sure is good enough to!


"I see 20/10 regularly."

What is the prevelence of 20/10 uncorrected? 20/10 best corrected? Are
they really 20/10 or are they guessing/memorizing the 20/10 line? Hey
if you want me to guess I might pass for 20/20 by getting 1 or 2
correct.


". I don't routinely test below 20/10 because my
exam rooms are not set up for it."


Woudlnt it be funny if any(even one) of them are a little or alot
better than 20/10? Almost all eyecharts only go down to 20/20, 20/15
and sometimes 20/10. Theres an eyechart online you can print that goes
below 20/10 at 20/8, 20/6, 20/5 and 20/4!


"There's a good reason standard eye
exam rooms are not set up to test for better than 20/10. Can you guess
what that is?"


guessing, memorizing, difficult to print such small letters, waste of
space on eyechart, way too rare for better than 20/10, protecting the
optometrist's sanity(yes some have fainted!)


"Your friend's claim remains pretty incredible, but aside from that..."


hey hes welcome to visit you or any creditable optometrist for proof.


"I'm curious about your concept of a "virgin" eye, one having "no
aberrations". Yes, LASIK can induce aberrations but it isn't usually
discussed without knowing which type of aberration you mean. Some are
more
annoying than others, and reducing one often raises another. I gather
you
think that's common?"


Virgin eyes have less aberrations than post lasik eyes. We can discuss
this fully over at the google groups lasik forums.


"That's a whole field in itself called "psychophysics." Most tests
aren't
accurate until you guess. And "majority" means "more than half.""


Hey I could go to a store and see a price tag from a distance and
"guess" what numbers are showing. Chances are I may end up correct. I
wont know if im right or wrong till I move closer. You could call me
20/25, 20/20, whatever you want to call me but I wont be seeing letters
as far as someone whos a true 20/20. Someone who sees half of the 20/20
could be considered 20/25+ but wont see quite as well as a full 20/20


"Refraction problems can result from poor communications, poor
instructions,
and poor technique on the part of the examiner. But you've had more
than one
doctor who couldn't get you to 20/20, right?"


occasioanlly, someone will get a bad refraction. I have never been
20/20 in my life. My eyes are good but not perfect enough to see 20/20
and the minification of -5 lenses doesnt help any and in fact makes
20/25 too small to reliabily see.


"I've examined a few like that. In some cases, corneal aberrations were

involved and they saw better with contacts than with glasses. In other
cases, refraction could be proven perfect and still there were limits
on how
well the vision could be corrected."

Just a few? No one in my family is true 20/20! Ive had friends who
bragged they were 20/20 but I could see signs as far away as they
could! One lady says shes 20/20(uncorrected!) and I had her read a sign
at an airport, moving closer till she could read it out correctly. I
had to move closer till I was 3/4 the distance. Do the math, this
doesnt make her quite 20/20. She could have 1/4 diopters myopia or
astigmastim, thats all it takes or the vision she saw was the best
vision she was going to have irreguardless. I know alot of friends who
actually have a very slight refractive error but its too slight to need
any action. Many may have 1/4 or 1/2 diopter astigmastim, myopia or
hyperopia. Some have more high order aberrations than others and
consequencly cant really see 20/20 while other eyes are much more
perfect and they see better than 20/20. True 20/20 is quite hard! Read
the excerpts I got off websites below.


You've heard the term 20/20 to describe healthy vision. But do you know
what it means? It's a standard devised to measure someone's eyesight
relative to the average. If you have 20/20 vision, it means that from
20 feet away, you can see what the average person sees from 20 feet.
Few people have this supposedly "normal" vision, considering that 61%
of Americans wear some form of corrective lenses.
People with poor eyesight have a higher second number. A person with
20/40 vision can only see from 20 feet what a person with normal vision
can see from 40 feet. 20/200 vision is considered legally blind in the
U.S.


JULIUS SHULMAN, MD: Well, it's possible now to see better than 20/20
with contact lenses, with glasses or with PRK and Lasik. These
procedures or contacts or glasses will let you see as well as your eye
will allow. Not everyone has the potential for 20/20. Some people
have 20/25, some 20/15. It's what your eye will allow.


I also read an article that says 1 in 4 people can fully see 20/20! See
the above, Julius even goes out to say that not all eyes have
potentional for 20/20, you see as well as the eye allows! Seeing less
than 20/20 does not neccessairly mean theres a disease, its just the
optics of the eye(cornea, lense, retina, etc)


"The everyday test for this is a pinhole. If you can see 20/25 through
a
pinhole held close to your eye, it's likely your problem is optical. If
you
can't see 20/30 through a pinhole, there may be some reason other than
optics."


I agree with you! I think some people are too quick to jump to the fact
if anyone isnt 20/20 they must have something wrong! I most certainly
see all of 20/25 in the left and half of 20/25 in the right with a
small pinhole in front of my glasses. Therefore I have an optical issue
limiting me, namely high order aberrations.


"But I can
tell you that it's "normal" for young, healthy -5 myopes to see 20/15,
minification or not. You have no minification when you wear contacts."


only if the eye allows this as Julius points out in the article. The
eye would need to allow for a little better than 20/15 to see 20/15
with -5 glasses but for contacts its not an issue. Anyone thats
correctable this good is lucky and fortunate to have very good optics
and few aberrations.


"After reading the 20/10 line, he--literally--read the patent number on

the bottom of the chart."


Thats another person with hypervision. What do you say he has? 20/6
vision?


"A question is fine. You posted about somebody having 20/4 vision."

no, I said 20/6 I said I have an eyechart that goes down to 20/4, you
can print eyecharts that go to anything you want(within the limits of
the printer of course)

 

20/10 is very good. Brag? I suppose so, although bragging in general
seems to be a sign of insecurity.

among young adults, probably 10%

20/10 best corrected?

among young adults, probably 30%

Are

Guessing is allowed, memorizing is not (any good VA measurer should have
a variety of letters to present, including tumbling Es, Landolt Rings,
and numerics. Random generators are the best, of course. 1 or 2 correct
does not get you 20/20. You have to get most of the letters, and if you
miss some, the 20/20 designation is appended with something like

20/20 -2 (meaning missed 2 letters on the 20/20 line, usually out of 6
presentations)

If you got all the 20/25 letters, and picked out 2 on the 20/20 line, I
would notate that as

20/25 +2

Theres an eyechart online you can print that goes

Why bother? Just take a 20/10 line and back the subject up to 40 ft.
away from it. Instant 20/5. Not exactly rocket science.

Wrong answers. It's that 20/10 is close to the threshold of
theoretically possible human acuity. No rocket science there, either.


w.stacy, o.d.

 

I looked on google and this is what I found.

"20/10 is
not undesirable; it is both highly desirable, and extremely rare."

"Seven out of ten
letters on any line is satisfactory."


"A small percentage of the population is blessed with vision better
than 20/20"


"Only about 35 percent of all adults have 20/20 vision without glasses,
contact lenses or corrective surgery. With corrective measures,
approximately 75 percent of adults have this degree of visual acuity
while the other 25 percent of the population just doesn't see very
well, Dr. Johnson says."


I also found websites that give different figures for 20/10 vision but
all say its extremely rare and one said 1 in 1000 see 20/10. How can
10% of adults be 20/10 if only 35% are even 20/20? You further add that
30% are 20/10 with glasses, which by the way minify so theyd have to be
BETTER than 20/10 to see 20/10 with glasses. How can 30% be 20/10 BCVA
when only 75% are even corrected to 20/20 or better? You appearently
dont see alot who cant see 20/20 but 25% cant which is a fair amount. I
dont know how you conduct your testing but I have to respectfully
disagree with you. Hey one opometrist considered me 20/20 with glasses
even though I could see none of the 20/20 line! As for guessing, theres
always the luck factor and if the person is borderline between two
lines, he could get lucky and guess his way. There is the phenomeon of
shape/blur reconization. The 20/10 line could look something like this:


...-.,,..,


The larger dots could be guessed between a choice of big letters like
E, H, F, the small roundish dots like an O, C, D. The long skinny dots
like an L, P, F. If you used numbers and didnt tell the person, he
would get everyone of them wrong, assuming they are letters and guess
on a best fit depending on the shape of the dot. There is a big
difference between actually being able to see the letters and guessing
on shape/blur reconization and getting some right with luck. Using
tumbling E's avoids this and gives a 25% chance. Test him with at least
10 different tumbling E's and also ask him to be honest, is he actually
seeing the E's or just guessing? Hey youd probably also consider me
20/20 if I had an eye exam at your office but I definately dont see as
well as a true 20/20. I had a 20/20 friend move closer and closer till
she could read the sign in the airport and I had to be quite a bit
closer to see it.

 

Please give a URL for that quote.

And that one. Satisfactory for what?

Nutty. I'd love a URL for that one.

Dr. Johnson? who is he? His numbers are whacked.

You further add that

What? Only MINUS Rx's minify. More than half the Rx's I write are +,
that's PLUS, or MAGNIFYING Rxs. These HELP people see smaller print.
What is wrong with you? Are you Otis' only child or what? Why do you
ignore the fact that MOST PEOPLE WEARING GLASSES ARE WEARING PLUS
LENSES, NOT MINUS LENSES!!!!!

How can 30% be 20/10 BCVA

What? Is it unreasonable that if 75% can see 20/20 or better that a
third of those will see 20/10?

Crazy, at least.

w.stacy, o.d.

 

you can find it all on google and then some. Here is one link
reguarding its rare to be blessed better than 20/20


http://ask.yahoo.com/20000726.html


"Dr. Johnson? who is he? His numbers are whacked."


Its common for doctors to disagree with each other. Sad to say, I have
to side with him. Considering so many people have all kinds of vision
problems, its not supprising in the least not to be 20/20 and at least
25% cant correct to 20/20 either. Ive told you my entire family cant
correct to a full 20/20 and alot of my friends cant either.


"More than half the Rx's I write are +,
that's PLUS, or MAGNIFYING Rxs. These HELP people see smaller print."


considering myopia is much more common and prevelent than hyperopia.
Also young hyperopes arent bothered much unless its severe or they do
alot of near work then they simply can use reading glasses.
post-presbyopic hyperopes see blurry at all distances so they
definately do need glasses and bifocals at that. You are right about
the magnification. Hey I think your testing their NEAR vision and they
are reading 20/10. This is perfectly normal and especially common for
hyperopes. I apologize for the confusion.


"What? Is it unreasonable that if 75% can see 20/20 or better that a
third of those will see 20/10?"


If were talking hyperopes with magnification plus glasses looking at a
near snellen chart then this is perfectly reasonable. Distance charts
are an entirely different beast.

 

and you told us one of your friends sees at 20/4...
So? I'm really confused as to your point or adgenda.

Do you have a question? Is it the one in the subject?
If you are asking the question why are you arguing
for your own answer? If you already have the answer
what is your adgenda? To amaze and impress? Are
you looking for recognition or support? What is it you
are trying to accomplish here? I thought the first one
or two exchanges were of interest but it's getting pendantic.

Maybe I just missed the point?

-Quick

 

There's this little thing called "physics". Sometimes they even call
them the "laws of physics". The limits of the printer don't define the
"laws of physics".

You are posting nonesense. Once again.

 

I never said 20/4 except that you can print an eyechart that goes down
to 20/4. He was claiming 20/6 vision. I have googled hypervision and
got some interesting articles. One article believes humans can
theoratically see up to 20/2.5! Thats nearly the 20/2 eagles see and
twice the 20/5 hawks see! Of course the wonderful thing called high
order aberrations is what limits "normal" human vision to 20/20 with
many actually seeing less than that and a few seeing better. I read
about bionic eyes where they can bypass the retina limit and dont even
get me started on the brain's limit but they say the brain is flexable
and can "learn" to see again compared to your old and now "terriable"
20/20. Damn imagine bionically altered eyes(replace your retina with
one with much more and denser cones?) and seeing like an eagle!