My problem was not the resolution, I could live with that. The problem is with optics: some areas of the screen are blurry. Depending on the particular unit you get (I had mine replaced once), the blurry areas are in different places. You might get a spot in the middle, or slightly to the side. If you fix your virtual display in place and move your head around, the blurriness will move across your virtual screen.

As I said, I had my glasses replaced because I thought I got a faulty unit, but the next one just had the blurry spots in different places. Then on a trip to Japan I visited several stores that had them on display and checked the display units — they all have the same problem.

I am not sure why, but not everyone is bothered by this. Perhaps some people don't care, or have had poor eyesight all along so they never saw the screen clearly. But for me there is a huge difference between seeing everything that's in front of me clearly and seeing blurry patches on my screen.