correcting vision better than 20/20

Can vision be safely corrected better than 20/20? I'm guessing there
must be tradeoffs of correcting vision with glasses, contacts, or laser
beyond 20/20.

 

Dear Bucky,

Subject: The "standard" 20/20.

Most people (no medical condition -- and young), will
have visual resolution of 1 minute-of-angle, or be
able to read 3/8 inch letters at 20 feet.

A number of people can have vision sharper than
20/20, with the use of a stronger minus lens.

Some ODs use this as a standard to prescribing
a minus lens, and this is called prescribing
for "Best Visual Acuity".

Most DMV tests require 20/40 with both
eyes, or 20/40 in the better eye, with no
lens.


Bucky wrote:

Otis> That is a "loaded" question. It depends on exactly
what you mean by "safely". Ther are those who
suggest that a strong minus lens accellerates
the development of nearsightedness. The
"jury" is still out on that subject. Some ODs
call the minus, "poision glasses for children."


I'm guessing there

Otis> That is a judgment you will have to make for yourself.

Best,

Otis

 

20/20 simply means that you see at 20 feet what a "normal" person sees
at 20 feet.

The goal in correcting vision is to give you the best possible, not some
arbitrary number.

 

This is all very interesting, Otis. WITHOUT pointing to any point of
your own anatomy, could you kindly cite your source for this
information?

Thanks.

 

As Regan once said, "There you go again!".

In fact, the vast majority of humans can see better than 20/20. Some do
so with a little plus. Some with a lot of plus. Some with some cyl.
Some with a zero power rigid contact lens. Some with no lens at all (in
fact MOST humans in the world fall into this category). And yes, some
do so with minus lenses. Some with WEAKER minus lenses, some with
moderate power minus, and yes, a few do so with strong power minus. So
what? Get over it.

w.stacy, o.d.

 

OK, I'm not talking about long term safety. I just mean "safely"
meaning you can wear that correction all day without getting a
headache. Can a typical nearsighted person be corrected to 20/5 or
20/1, or what's the limit?

 

So why not attempt to correct nearsighted people's vision to 20/5 or
20/1? Isn't that better than 20/20?

 

Yes it is, but the AVERAGE of a population was measured
and established to be about 1 minute-of-arc resolution.

Or the AVERAGE person could be "corrected" to 20/20,
or reading 0.9 cm letters at 6 meters.

Obviously, some can do better, and some can not
read this size letters.

In recognition of this fact, the DMV departments had
set their standard as reading 1.8 cm letters at 6 meters.

Because some people can not even be "corrected"
to 20/20.

Best,

Otis

 

In my experience when the lens was made stronger (beyond optimal) the acuity
didn't improve. I just experienced discomfort and realized I needed a
better optometrist.

 

To those that may care recent research has determined that if use the
photoreceptor density in the fovea, part of the eye that gives most
detailed vision in normal eyes, the estimate for acuity is around 20/8,
believe it or not. Now that is not the entire story, the light gets
scattered/reflected/lost a little bit while traveling through the eye
detracting from this 20/8 possibility.

I can see 20/15+ with both eyes, corrected with toric soft contact
lenses, anything less and I go nuts. However, not everyone
needs/appreciates better acuity, but most are happy with 20/20. The
reason for the 20/20 can have a lot to due with leading an exam, if
20/20 acuity or better is met you can rule out a lot of pathology or
additional problem, if 20/20 is not met investigation as to why is
necessary.

Sorry to be long winded.
ODTOBE

 

They better be happy. By definition, 20/20 is "normal" vision.

 

Ahh, thank you, that was a helpful analogy.

How about lenses that also magnify then? Let's say a baseball player
who is 20/20 wants to be 20/10. Could he get lenses that magnify to
achieve that resolution? In this case, I suppose that the tradeoff
would be field of view. But is this possible?

 

Dear Bucky,

Bucky> How about lenses that also magnify then? Let's say a baseball
player

Yes, a 4 power telescope will provide that type
of angular magnification -- but not very practical.

Otis

=============

 

Dear Bucky,

Please disregard Otis's postings. He is not in the medical profession and
not in any position to give medical advice.

Thanks!

Allen

 

Ok otis, now you amaze me. You actually made a statement that makes
sense. I'm dumbfounded. I don't know what to say. If you are that
smart, why then do you keep posting the other nonsense stuff on this
newsgroup?


w.stacy, o.d.

 

Ok otis, now you amaze me. You actually made a statement that makes
sense. I'm dumbfounded. I don't know what to say. If you are that
smart, why then do you keep posting the other nonsense stuff on this
newsgroup?

Otis> Thanks!

Otis> And as you might know, I do have friends in both ophthamology
and optometry. But we respect each other. They have been
wonderful.

Best,

Otis


w.stacy, o.d.

 

For absolute proof of that, just look at people's
eyeglasses -- how clean/dirty they are!

(Likewise, check out their cars' windshields -- same
thing!)


David