Weigh My Rack reviews the EyeSend belay glasses. They note that "The adjustment makes a particular difference if your climber is on vertical to steep overhang. Even while using traditional belay glasses, the belayer would need to tilt their head to follow a climber who is on a steep overhang."
"During our field testing, we used the EyeSend Adjustable-View Belay Glasses while watching a variety of terrains from slab to overhanging climbing and in each instance we were able to keep our neck straight during the entire belay."
Excerpt: "A robust set of belay glasses, with the extra adjustment function, a sturdy case to protect them and cleaning cloth to wipe off the inevitable smears. Pretty much the best glasses I’ve tried out".
PitchSix, LLC announced today that it has launched a Kickstarter campaign for the EyeSend Adjustable-View Belay Glasses. These are the first belay glasses on the market that allow you to adjust the field of view.