I can't tell you the exact font size but being in the same category and needing glasses for close vision, in that regard I've not had a problem with the FR265. There is no discreet setting for the font size that I know about, but it can be manipulated by the choice of Watch face and for activities the number of variables displayed on the screen. To get a lager front in activities choose less variables to display and add another screen.
While I'm not pleased with the Optical HR processing, I do really like the display! It's a substantial improvement in clarity and brightness over my FR245
