I've seen it on a video before People staring a few feet from a wall, I believe they were zen Buddhist staring at a wall. From what I've heard a lot of zen practioners do strong sits, for me I'd rather stare at a blank wall, this practice is already hard enough, I'd rather not look at anything to make my mind wonder more & yes I agree when you build yourself up to the 2 hour mark you defiantly start to get monkey mind & start asking yourself if you set the clock wrong, thought I was the only one thanks ? Also I do self inquiry at the same time I do the strong sits.