Let's Photograph Comet 46P Wirtanen

On Wednesday, December 26, 2018 at 4:39:50 PM UTC-5, Paul Schlyter wrote:



No he wouldn't. My local eye doctor wouldn't even say 20/30, she
would say 0.67 perhaps rounding it to 0.7 - as would most European
eye doctors. The 20/xx stuff is an American idiosyncracy.

Since most doctors worldwide would describe visual acuity as 20/20 or 6/6, your Swedish eye doctor's notation would be the idiosyncracy.

Look, we get that you don't like the USA or anything much about it. So let's get this back on topic and talk about amateur astronomy and how difficult it must be to observe from Stockholm.

On Wed, 26 Dec 2018 22:39:47 +0100, Paul Schlyter
wrote:

I havent a clue. All I can say is that maybe your local eye doctor
might
have an answer.

No he wouldn't. My local eye doctor wouldn't even say 20/30, she
would say 0.67 perhaps rounding it to 0.7 - as would most European
eye doctors. The 20/xx stuff is an American idiosyncracy.

No, that's not at all what your local eye doctor would do. If he were
using a Snellen test to screen your visual acuity (as is common all
over the world, including Sweden), he would properly express your
results as a Snellen fraction, defined by European ISO 8596, giving
both the numerator (distance) and the denominator (a normalized
distance). The fraction is never reduced. The only difference between
the American and the European fractions is that in Europe it's
normally metric. In the U.S. we have 20/20 as normal vision, in Europe
it's 6/6.

The Snellen fraction is most certainly not an American idiosyncrasy.

Paul Schlyter:
No he wouldn't. My local eye doctor wouldn't even say 20/30, she
would say 0.67 perhaps rounding it to 0.7 - as would most European
eye doctors. The 20/xx stuff is an American idiosyncracy.

And Canadian, Middle Eastern, Chinese, Indian, South American,
Japanese, Indonesian... Time tested and proven.

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm

Chris L Peterson wrote:
[…] he would properly express your results as a Snellen fraction,
defined by European ISO 8596,

As the name already indicates, standards with prefix “ISO” (International
Organization for Standardization) is NOT a “European” standard, but an
*international* one.

--
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

On Thu, 27 Dec 2018 13:59:24 +0100, Thomas 'PointedEars' Lahn
wrote:

Chris L Peterson wrote:
[…] he would properly express your results as a Snellen fraction,
defined by European ISO 8596,

As the name already indicates, standards with prefix “ISO” (International
Organization for Standardization) is NOT a “European” standard, but an
*international* one.

Not all ISO standards are adopted by all ISO body members. ISO 8596 is
adopted by all the European members. And the point here is that we're
discussing a European country.

On Wed, 26 Dec 2018 20:11:23 -0500, Davoud wrote:
Paul Schlyter:
No he wouldn't. My local eye doctor wouldn't even say 20/30, she
would say 0.67 perhaps rounding it to 0.7 - as would most
European
eye doctors. The 20/xx stuff is an American idiosyncracy.

And Canadian, Middle Eastern, Chinese, Indian, South American,
Japanese, Indonesian... Time tested and proven.

And awkward. It is unnecessarily complex.

On Wed, 26 Dec 2018 17:11:40 -0700, Chris L Peterson
wrote:
On Wed, 26 Dec 2018 22:39:47 +0100, Paul Schlyter
wrote:
I havent a clue. All I can say is that maybe your local eye
doctor
might
have an answer.

No he wouldn't. My local eye doctor wouldn't even say 20/30, she
would say 0.67 perhaps rounding it to 0.7 - as would most European
eye doctors. The 20/xx stuff is an American idiosyncracy.

No, that's not at all what your local eye doctor would do. If he
were
using a Snellen test to screen your visual acuity (as is common all
over the world, including Sweden), he would properly express your
results as a Snellen fraction, defined by European ISO 8596, giving
both the numerator (distance) and the denominator (a normalized
distance). The fraction is never reduced. The only difference
between
the American and the European fractions is that in Europe it's
normally metric. In the U.S. we have 20/20 as normal vision, in
Europe
it's 6/6.

The Snellen fraction is most certainly not an American idiosyncrasy.

Then how come the last time I had my eyes examined I got a visual
acuity of 1.1 on my left eye and 1.2 on my right eye?

On Thu, 27 Dec 2018 17:22:59 +0100, Paul Schlyter
wrote:

On Wed, 26 Dec 2018 17:11:40 -0700, Chris L Peterson
wrote:
On Wed, 26 Dec 2018 22:39:47 +0100, Paul Schlyter
wrote:
I havent a clue. All I can say is that maybe your local eye
doctor
might
have an answer.

No he wouldn't. My local eye doctor wouldn't even say 20/30, she
would say 0.67 perhaps rounding it to 0.7 - as would most European
eye doctors. The 20/xx stuff is an American idiosyncracy.

No, that's not at all what your local eye doctor would do. If he
were
using a Snellen test to screen your visual acuity (as is common all
over the world, including Sweden), he would properly express your
results as a Snellen fraction, defined by European ISO 8596, giving
both the numerator (distance) and the denominator (a normalized
distance). The fraction is never reduced. The only difference
between
the American and the European fractions is that in Europe it's
normally metric. In the U.S. we have 20/20 as normal vision, in
Europe
it's 6/6.

The Snellen fraction is most certainly not an American idiosyncrasy.

Then how come the last time I had my eyes examined I got a visual
acuity of 1.1 on my left eye and 1.2 on my right eye?

Because you have an incompetent eye doctor who doesn't observe
standards? Maybe a homeopath or some other quack?

Chris L Peterson wrote:
[…] Thomas 'PointedEars' Lahn […] wrote:
Chris L Peterson wrote:
[…] he would properly express your results as a Snellen fraction,
defined by European ISO 8596,

As the name already indicates, standards with prefix “ISO” (International
Organization for Standardization) is NOT a “European” standard, but an
*international* one.

Not all ISO standards are adopted by all ISO body members. ISO 8596 is
adopted by all the European members.

Cite evidence.

--
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

On Thu, 27 Dec 2018 23:30:35 +0100, Thomas 'PointedEars' Lahn
wrote:

Chris L Peterson wrote:
[…] Thomas 'PointedEars' Lahn […] wrote:
Chris L Peterson wrote:
[…] he would properly express your results as a Snellen fraction,
defined by European ISO 8596,

As the name already indicates, standards with prefix “ISO” (International
Organization for Standardization) is NOT a “European” standard, but an
*international* one.

Not all ISO standards are adopted by all ISO body members. ISO 8596 is
adopted by all the European members.

Cite evidence.

No. You're not worth the effort.