Personally, I have to close my eyes. If I don't, it's a complete turn off. But, again, that's just me. I prefer to keep them shut because I hate the strain on my eyes. It's awkward to keep them open, too, especially if the other person has their eyes open and we're both just staring at each other. Weird! When I close my eyes, I can focus solely on the feelings and sensations. I don't over think anything that way. I can feel their lips, their breath, their hands, even their heartbeats sometimes. In a way, it's more bonding if both people have their eyes closed. Everything is based on feelings and sensations that way and you get to explore the other person blindly at any pace you'd like because they're doing the same thing. I'm not really a visual person, either, so having my eyes open while kissing would only be a huge distraction for me.