I was reading a recent Sports Illustrated article about SF Giants
first-baseman Will Clark. The article mentioned that Clark has 20/12
vision in both eyes, and that famed ex-Red Sox hitter Ted Williams had
20/10 vision. The article suggests that better than "normal" vision
might be a factor in the success of these two baseball players (although
Clark is not hitting well of late– perhaps he needs glasses? 
Although I myself have no delusions of ever being able to play
in the Major Leagues, I do think that being able to see "better" is a
nice idea– hence my question for netland optometrists/opthamologists:
Why are lenses not perscribed to correct myopia (or anything else– I’m
myopic myself) to "better" than twenty/twenty? Is this for some reason
physically (optically?) impossible? Or does it result in unwanted
"side-effects" such as making everything look really itty-bitty small?
Or is it just a conspiracy to keep me from playing baseball?
Any leads appreciated! Thanks.
barb…@gang-of-four.stanford.edu
Sharpness of vision depends on a lot of things, such as the length of the
eyeball versus the focal length of the lens, the flexibility,
transparency, and shape of the lens, the transparency and condition of the
humor, the condition of the retina, and the signal processing ability of
the visual cortex. Vision correction via lenses and RK can only improve
the matching of the focal length of the lens with the length of the
eyeball and, to a limited extent, irregularities in the shape of the lens.
Fortunately, these are usually the dominant problems. The other big one,
the stiffening of the lens as it ages, is usually treated by having more
than one prosthetic lens. You can only get the focusing so good. The
rest is up to those other factors, which vary from person to person.
20-20 is just a reference point, like "8th grade reading level" or "100
IQ."
As real examples, my left eyeball does 20/15 when properly corrected.
However, my right eyeball probably can’t ever do better than about 20/20.
I once had a friend who, even with the proper prescription, could not see
better than about 20/80 as a result of some retinal damage.
I think the baseball players of which you speak are just lucky.
Eric Pepke INTERNET: pe…@gw.scri.fsu.edu
Supercomputer Computations Research Institute MFENET: pepke@fsu
Florida State University SPAN: scri::pepke
Tallahassee, FL 32306-4052 BITNET: pepke@fsu
Disclaimer: My employers seldom even LISTEN to my opinions.
Meta-disclaimer: Any society that needs disclaimers has too many lawyers.
In article <1990May30.222309.3…@Neon.Stanford.EDU> barb…@Gang-of-Four.Stanford.EDU (Barbara Chapman) writes:
>Why are lenses not perscribed to correct myopia (or anything else– I’m
>myopic myself) to "better" than twenty/twenty?
They are, aren’t they? It was quite a few years ago, but I’m quite certain
that when I first got contact lenses, my eye doctor told me that my vision
would be corrected to 20/15. Was he fibbing? Doctors?
A.
BC> barb…@Gang-of-Four.Stanford.EDU (Barbara Chapman)
BC> I was reading a recent Sports Illustrated article about
BC> SF Giants first-baseman Will Clark. The article
BC> mentioned that Clark has 20/12 vision in both eyes, and that
BC> famed ex-Red Sox hitter Ted Williams had 20/10 vision. The
BC> article suggests that better than "normal" vision might be a
BC> factor in the success of these two baseball players (although
BC> Clark is not hitting well of late– perhaps he needs glasses?
BC> :-)
BC> Although I myself have no delusions of ever being able
BC> to play in the Major Leagues, I do think that being able to
BC> see "better" is a nice idea– hence my question for netland
BC> optometrists/opthamologists:
BC> Why are lenses not perscribed to correct myopia (or anything
BC> else– I’m myopic myself) to "better" than twenty/twenty? Is
BC> this for some reason physically (optically?) impossible? Or
BC> does it result in unwanted "side-effects" such as making
BC> everything look really itty-bitty small? Or is it just a
BC> conspiracy to keep me from playing baseball?
BC> Any leads appreciated! Thanks.
First of all, "20/20" does not equate with "normal" vision! Instead, 20/20
is the "average" vision among "normal" people. 20/30 or better is considered
to be normal visual acuity. Therefore, 20/15 and even the rare 20/10 is
just "within normal limits" for human visual acuity.
I routinely correct my patients to better than 20/20 — for those whos’
eyes are able to see better than 20/20 with the correct lenses, that is.
I doubt there is a conspiracy to keep you from playing baseball (unless it
is one based on sexual discrimination).
There is, however, another visual factor which keeps many individuals from
moving up to the majors. That factor is "Eye Dominance". Just as one is
either right handed or left handed, each person has a preferred eye. Several
studies done by Optometrists who specialize in Sports Vision have shown that
baseball players who consistently hit well (over 300) have "Cross Dominance"
righty sights the ball with his/her left eye…
Well, if you want to see as clearly as you possibly can, go see a good
Optometrist and ask to be corrected to "BVA". Gas permiable rigid contact
lenses often give better vision than glasses so you may wish to try them.
Steve
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In an article of <30 May 90 22:23:09 GMT>, barb…@Gang-of-Four.Stanford.EDU
(Barbara Chapman) writes:
BC>Why are lenses not perscribed to correct myopia (or anything else– I’m
BC>myopic myself) to "better" than twenty/twenty? Is this for some reason
BC>physically (optically?) impossible? Or does it result in unwanted
BC>"side-effects" such as making everything look really itty-bitty small?
BC>Or is it just a conspiracy to keep me from playing baseball?
Whether you will see better than 20/20 is not so much a factor of the
correction but the potential for better vision of your eyes – their accutance.
Some eyes have the potential to resolve smaller print than the "standard"
Snellen 20/20 (for example my vision is 20/13). Occasionally an eye by itself
will only resolve to 20/25 but with both eyes the vision may exceed that –
reinforcement. This should tell you that vision is something more than just the
ability to read high contrast letters. Contrast discrimination is also a
factor.
Most eye doctors strive to obtain the best corrected vision possible for the
patient – what wver level that may be. There are still a few who undercorrect
for some esoteric reasons but these are in the minority.
Leo Bores, M.D.
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