If you are happy with the 125 size try ....
Control Panel > Fonts > Adjust Clear Type Text.
This will run you through some screens where you can adjust the
fonts to suit your vision, and may help reduce the blur.
If you have not already, try setting the custom option ('not recommended' - Yeah! right.) @ 115 or 120, which you
may find a bit crisper but still large enough.
I use 120 @1080p with a 24" monitor. I've left the 'Let Windows fix...' option off as I don't think Windows knows what
best suits my eyes and I don't want it to mess with my Clear Type setup.
Now I wish MS could get their act together and make it possible to use different settings when running
two monitors as I need 130 with my main 27" 1440p monitor, but find this a bit too large for the 1080p second monitor.