https://www.techradar.com/news/the-latest-oculus-prototype-would-let-you-see-more-than-ever-before

When it comes to using a virtual reality (VR) headset, no matter how good the display is, what you see will always be limited by how wide the headset's field of view. 

Most of the best VR headsets on the market, like the Oculus Rift, PlayStation VR and HTC Vive, have a 110-degree field of view, which is actually pretty good, but you will still see the edges of the headset once you look outside of this boundary.