I am a recently retired webmaster and fortunately have fewer eye problems than most people my age. I have astigmatism and, in common with most people over 40, have reduced accommodation. Perhaps because I have spent considerable time in front of computer screens my eyes focus most easily at screen distance. I use low power long distance glasses to watch television and drive after dark. I use low power reading glasses for small print such as maps and repairing small items. Most of the time I don't need glasses.
There is no such thing as standard settings for font size or style. It is entirely a matter of personal preference.
Here are my settings:
34cm x 27cm Apple Studio Display set to millions of colours and a resolution of 1280 x 1024
Safari 'standard' font set to Geneva 14
Safari fixed width font set to Courier 14
Default encoding set to Western (ISO Latin 1)
Minimum font size set to 10
Geneva is a very old Apple font optimised for screen use. I still find it more readable than other fonts under a wide range of conditions.
I assume you know about Zoom settings to override the above:
cmd + to increase size
cmd - to decrease size
cmd 0 to return to 'normal' size
I set 'Zoom Text Only' on the view menu.
You can also create your own style sheet to obtain even more control. Here is a Google search link about these:
https://encrypted.google.com/search?q=browser+%27style+sheet%27+%27visually+impa ired%27&as_qdr=all&newwindow=1&num=100
I have written many style sheets but not for visually impaired. I am happy to assist if required.
