9-Hole Reviews discuss the "occluded gun sight" technique, where a shooter uses a red dot optic with a solid front cover, forcing them to shoot with both eyes open. They share their experience using this method in a deployed environment to retain the benefits of a kill flash without compromising optical clarity. They explain its value as a training tool for developing both-eyes-open shooting and discuss why some optics come with a clear rear cover and a blacked-out front, which prevents flashing and mimics a kill flash. Additionally, they note that this technique is viable for LPVOs, provided they have an illuminated reticle.