I too only use one eye, my left one in particular as my right one is no good.
To top it all off I prop up my glasses on my nose so that the left lens is slightly farther away from my eye making it as if I'm sort of zooming in, this is how I draw and do my job, pretty much anything on a monitor or piece of paper, so im used to it and isn't an issue, but it does mean I see an even smaller portion of the screen.

Generally I don't have issues but reading tiny messages that pop up, seeing the number of stacks when tanking and such IS an issue.
I have my target and focus target bars set to max size but reading the number of stacks can still be an issue though over time I've learned to distinguish the blurs but I tend to steer clear from hardcore/endgame content because of my vision and the fact that I take much longer to see/notice stuff.

And yeah, I'm a tank, got my Zeta and Bear and all
dunno why the forums say my main class is Arcanist