I bought them hoping to ensure/enhance Visual Line Of Sight requirements; as looking down at a display and then trying to reacquire sight of the UAS at distance can be a challenge. I wear glasses and it can be cumbersome to wear the glasses under the BT-300's. I had lenses for the insert made, but I can't resolve the issue of trying to have focus on both the image and UAS. Thus, they're not what I need and I have no further use for them.