It might just be those glasses, but the other issue to be cautious of is where the IR camera is and looking at it. In my 950 xl, although the IR light lights up on the top left of the phone, the actual camera is in the top RIGHT corner. What I started doing a while ago is, before turning the phone on, I look at my reflection in the black mirror like surface. I position my eye reflection over the camera. Then I turn it on. That gives me almost instantaneous recognition and unlocking. After a while, you have a better idea of how to hold the camera so that it is looking at your eye without having to see the reflection.