Do you know which HMD (head mounted display) or headset it was?

following things to consider when blurry:

• IPD (Inter-pupillary distance) of the lenses (there are fixed (just software IPD) and better with mechanical slider -> if you have a very small (<=60mm or very high >=75mm) you can get problems
• sweetspot area which means how tolerant is the headset if you move it relatively to your eyes, some have a wide range for sweetspot others not -> just try to move the headset in another position on your head, try to fasten it if too loose (PSVR works if you move the headset up or down e. g.)
• resolution per eye currently ranging from 960x1080 (PSVR) up to 3840x2160 (Pimax 8k) which can make a huge difference in sharpness, readability of text, but also depends on the used FOV, what counts is ppi (pixels per inch) e. g. very high in the HP Reverb 1058pp for example with a horizontal FOV of about 105°
• display type e. g. AMOLED or LCD combined with glare/godray effect, but current gen is quite good except the Index has some minor problems with that, but overall not so important
• bad resolution setting in software because of a demanding app/game like in current No Man's Sky which still has no Pro Patch for PS4 e. g. quite blurry