>>303356912
It's a normal thing called the vergence accommodation conflict. The display is just a flat screen and the headset lens optically move it back to 2 meters away from your eyes. When you try to focus on some object that's virtually closer than 2 meters, you eye's own lenses will try to adjust their focus, and your eyes will swivel inward to point at the (virtual) object. However, the screen is still at 2 meters out, so your eyes attempts just make the image blurry.

Eventually (after a few hours in VR) your brain will learn that trying to accomodate when looking at close objects doesn't work, and you'll be able to keep focus. But then back in the real world, you'll experience the opposite effect where things stay blurry when before they'd be in focus (because of accomodation).

http://doc-ok.org/?p=1602