This is also in the Sam Harris blog I posted earlier. I’m putting it in separately because I think it’s such an important notion to consider.
“It’s also useful to do this practice with your eyes open, because vision seems to anchor the feeling of subject/object duality more than any other sense. Most of us feel quite strongly that we are behind our eyes, looking out at a world that is over there. But the truth – subjectively speaking; I’m not making a claim about physics – is that everything is just appearing in consciousness. Losing the sense of subject/object duality with your eyes open can be the most vivid way to experience this shift in perception. That’s why Dzogchen practitioners tend to meditate with their eyes open.”