The entire screen is perfectly sharp for me. Seems you're concentrating on trying to make them not work instead of just using them.
BS, you're lying to yourself or you don't know what your talking about. Close an eye and see if you can see the entire screen. Now switch open eyes and notice the same. You can clearly see that not all of the screen is visible with each eye. Those areas that only one eye is seeing is hard to see as you're not getting stereoscopic vision on it. Also, because they choose to use a complex prism/polarizer system and two screens instead of just one screen, convergence is not perfect.
Tim