Diagnosis
This is a side effect of the aggressive 1000R curve on a VA panel, combined with maybe some suboptimal ClearType settings in Windows. The extreme curve can cause slight distortion at the very edges.
How to Fix It
Run the Windows ClearType Text Tuner. Search for 'Adjust ClearType text' in the Start menu and follow the steps, making sure you select the text boxes that look sharpest to you. Then, on the monitor itself, press the joystick and go to Picture > Sharpness. The default is 60. Try adjusting it down to 56 or up to 64 to see what looks clearest for text.
If That Didn't Work
Check your scaling in Windows Display Settings. Avoid weird percentages like 125%. Stick to 100% or 150%. Also, ensure the monitor's resolution is set to its native 2560 x 1440 in your graphics driver control panel.
Heads Up
The 'Response Time' setting in the OSD under 'Game' can cause overshoot ghosting (coronas around text) if set too high. If text has colored fringes, try setting Response Time from 'Faster' down to 'Standard' or 'Fast'.