Uneven Screen Bightness on X200 Tablet

[Life-is-easy]

Hi, I got an x200 tablet from EBay and everything wors like a champ. The machine looks brand new with all orginal stuff. However, after 15 mintues learning the stylus pen operation I got very tired. The reason I believed is the uneven brightness on the LED backlighted screen. When I moved my head left to right several inches relative to the screen, I can clearly tell the diming on the 4 edge area depending which direction I move to. It feels like a polarized layer on top of the screen that gives this ennoying effect.

When I look at a regular LCD monitor, it doesn't do this. I also borrowed a Motion Computing Tablet (5-6 years old), it is giving even brightness regardless if I viewed it at an angle or normal to the screen. So, my conclusion is that the X200 needs improvements on the screen design. I called Lenovo, no suggestion at all. I don't want to send the PC to a service depot as I don't think replacing the screen will improve anything, but will cause many new problems when they open it up. Can someone tell me how to live with this problem?

Thank you so very much!!