I have a MacBook Pro (Retina, 15-inch, 2015) connected to 2 LCD monitors: one through VGA and one through DVI. Text in both this monitors look awfully blurry.
Things I've tried:
Settings > Preferences: Font smoothing enabled/disabled (makes no visual difference at all).
AppleFontSmoothing set to 0, 1, 2, 3.... also no visual difference.
The edid patch to foce RGB also didn't work (applied the patch succesfully but didn't make any visual difference). Didn't remove it though and my color profile is set to 'Forced RGB'.
Same monitors in a Windows machine don't present this problem (at least the one connected through DVI, VGA looks a little off too but that might be the connection).
Edit: Additional details. Monitors are both the same, Lenovo E2323. No settings aside from contrast, brightness, colors, clock... basic stuff.