Getting mild eyestrain staring at an external monitor connected to Macbook Pro running Windows 8

I bought my monitor, Samsung SyncMaster SA300, over 10 years ago as a part of my desktop computer. I had been using Windows XP and 7 since then without any eye problems. About 5 years ago, I switched to Macbook Pro 13'' 2011 running Mac OS X Lion, and I connected it with that monitor. I still got no problems. When I upgraded OS X to Mavericks, my eyes hurt after staring at the laptop about half an hour, but they were fine staring at the external monitor.

Then, I installed Windows 8 on my Macbook Pro, and i got mild eye strain staring at the external monitor for about 15 minutes, but no issues with the Macbook Pro's screen. The display profiles of both screens are the same, sRGB IEC61966-2.1. 

It wasn't comfortable staring at the screen all day, and I was afraid it might harm my eyes in the future so I tried other profiles installed on the computer but none of them worked. Then, i tried this one, Samsung SynMaster F2380, from this website, and at first, I felt the relaxation in my eyes, but after trying it for about an hour, it's hard to open my eyelids but no pain nor eye strain.

Finally, I found the solution. It's installing the monitor's driver. I checked the Device Management and the monitor's name was Generic PnP Monitor. After installing the driver from here, its name changed to SyncMaster S20A300B / S20A350B (Digital). 

And I also modified the Device Profile of the external monitor as following:

The problem was gone, and I could stare at the screen all day with no problems.