What i think you're experiencing is monocular vision, i've found the vr players i have used default to monocular vision when you open up the menu, basically it shows the video only from a single eyes pov. There generally will be an option in one of the players settings to toggle this setting on and off.
As to why its blurrier, this is entirely a guess, but for me personally i experience the same thing as i have a bad eye so my brain focuses only on my good eye for vision, so when i view vr with both eyes i tend to find it somewhat blurry as it mixes in both eyes pov, but find it a lot clearer when i switch to mono. You might unknowingly share a similar problem with your eye.
