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Random Snellen Eye Chart Generator
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| plpfoot@gmail.com 2006-05-01, 1:22 am |
| Just figure one out...a 20/20 E subtends an angle of 5 minutes of one
degree at 20 feet away. A 20/40 E subtends 5 minutes of arc at 40
feet, etc. This means that the 20/60 letter will be 3 times the size
of the 20/20 letter. For small angles the sine of theta is theta.
Don't forget to use radians. It is not a valid test if it is closer
than 20 feet because refraction begins to enter into the equation.
Ted.
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| otisbrown@pa.net 2006-05-01, 1:22 am |
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Or to make it clear:
20/20 means 0.9 cm letters at 6 meters
20/40 means 1.9 cm letters at 6 meters.
etc.
Otis
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| otisbrown@pa.net 2006-05-01, 1:22 am |
| Or to make it clear:
20/20 means 0.9 cm letters at 6 meters
Or 6 x 0.0015 = 0.009 meters
(Approximately)
20/40 means 1.8 cm letters at 6 meters.
etc.
Otis
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| otisbrown@pa.net 2006-05-01, 1:22 am |
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Or Gary, if that fails, just use the
neat Random Snellen on my site:
www.myopiafore.com
As eye-chart 2 (IVAC)
Very easy to use -- and you
can not memorize the letters.
Best,
Otis
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| otisbrown@pa.net 2006-05-02, 1:26 am |
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Dear Gary,
Subject: Substitute Random Snellen.
There is an easy-to-use Snellen
on my site (IVAC) as
eye-chart 2, on the lower
right side.
www.myopiafree.com
Hope that meets your requirement.
Otis
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| Neil Brooks 2006-05-02, 1:26 am |
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otisbrown@pa.net wrote:
> Dear Gary,
>
> Subject: Substitute Random Snellen.
>
> There is an easy-to-use Snellen
> on my site (IVAC) as
> eye-chart 2, on the lower
> right side.
>
> www.myopiafree.com
>
> Hope that meets your requirement.
>
> Otis
I would simply advise that you *strenuously* avoid the book that he's
selling on that site.
At $24.95 for 129 pages, or 19 cents per page, that's very expensive
toilet paper.
Take care,
Neil
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| A Lieberman 2006-05-02, 1:26 am |
| On 1 May 2006 19:44:20 -0700, Neil Brooks wrote:
> I would simply advise that you *strenuously* avoid the book that he's
> selling on that site.
>
> At $24.95 for 129 pages, or 19 cents per page, that's very expensive
> toilet paper.
Oh geeez, here he said he didn't make any money from his website.
Hmmm, maybe I need to post after each one of his posts to avoid the
spammer.
Allen
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| Neil Brooks 2006-05-02, 1:26 am |
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"A Lieberman" <lieberma@myself.com> wrote in message
news:1a75bx44q2j6y$.qbn5loc5x5nt$.dlg@40tude.net...
> On 1 May 2006 19:44:20 -0700, Neil Brooks wrote:
>
>
> Oh geeez, here he said he didn't make any money from his website.
>
> Hmmm, maybe I need to post after each one of his posts to avoid the
> spammer.
>
> Allen
Ohhhh, no. He's still in the business:
http://www.i-see.org/otis_brown/
I think he advertises it on his site, too.
I felt better when I thought he was just insane. Now I realize he's just
in it for money.
I think this is worse....
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| Thanks for the replies, however I did contact the site owner and the zip
archive has now been fixed :-)
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