@theluggage ,
I wrote it badly, I meant 7" difference.
And I mainly wrote it to show that the difference is quite small and there not so much point to draw sharp line somewhere, when "there's enough resolution".
It is just about individual behavior how far you keep your eyes from the monitor.
Which usually does differ comparing if you use only one monitor or several of them.
I had much bettervision than 20/20 when I was young, especially the left eye.
Now that I'm over 50, my vision has degraded to mortal levels. So I don't need or want supersharp anything anymore.
First step to "enough resolution" is not to be able separate rgb-subpixels. Some of us remember the time, when that defined the viewing distance of crt-tv.
How much data is resolved can be measured by MTF curve.
en.wikipedia.org
says that: "The best
visual acuity of the human eye at its optical centre (the fovea) is less than 1 arc minute per line pair, reducing rapidly away from the fovea."
So that the two pixels, other being black and other white, for not being perceived as one gray dot, I'd say 2px / arc minute is good "rough point".
And the print industry didn't stop to 300dpi because it was perfect, it stopped there, because it was practical. Pretty much same thing than with cd audio etc.
Somehow it is usually forgotten that SJ said "from 10" to 12"" and just one number is picked from there...
Retina display was a practical decision, not some scientific theoretical limit.