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:


> Can vision be safely corrected better than 20/20?

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
> must be tradeoffs of correcting vision with glasses, contacts, or laser
> beyond 20/20.

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

Best,

Otis

In article <(E-Mail Removed). com>,
"Bucky" <(E-Mail Removed)> wrote:

> 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.

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.

--
Dan Abel
(E-Mail Removed)
Petaluma, California, USA

(E-Mail Removed) wrote:
> 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:
>
>
> > Can vision be safely corrected better than 20/20?
>
> 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
> > must be tradeoffs of correcting vision with glasses, contacts, or laser
> > beyond 20/20.
>
> Otis> That is a judgment you will have to make for yourself.
>
> Best,
>
> Otis

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.

(E-Mail Removed) wrote:
>
> A number of people can have vision sharper than
> 20/20, with the use of a stronger minus lens.

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.

(E-Mail Removed) wrote:
> 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.

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?

Dan Abel wrote:
> The goal in correcting vision is to give you the best possible, not some
> arbitrary number.

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

Bucky wrote:
> Dan Abel wrote:
> > The goal in correcting vision is to give you the best possible, not some
> > arbitrary number.
>
> 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

"Bucky" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
> Dan Abel wrote:
>> The goal in correcting vision is to give you the best possible, not some
>> arbitrary number.
>
> So why not attempt to correct nearsighted people's vision to 20/5 or
> 20/1? Isn't that better than 20/20?
>
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

VicTek wrote:
> "Bucky" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed) ups.com...
> > Dan Abel wrote:
> >> The goal in correcting vision is to give you the best possible, not some
> >> arbitrary number.
> >
> > So why not attempt to correct nearsighted people's vision to 20/5 or
> > 20/1? Isn't that better than 20/20?
> >
> 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.