Science says it's all about the feeling.
If you were to deconstruct a simple romantic kiss, it might look something like this: Lean in, close your eyes, and pucker up. No matter how kisses differ—in partners, in levels of passion—it seems as if we've all been trained to never (we repeat: never) open our eyes during a kiss. But why is this the case? How did it come to be such a ubiquitous rule that we all—each and every one of us—always close our eyes when we kiss?Well, we did some digging, and the answer has nothing to do with tradition. It's all in the science.According to a study published in the Journal of Experimental Psychology: Human Perception and Performance, you likely close your eyes instinctively during a kiss, as the research shows that performing a challenging visual task could reduce your ability to comprehend stimuli associated with the other senses—in this case, touch. In general, humans aren't that adept at using all of their senses simultaneously. (This explains, for example, why you might not notice your phone vibrating in your pocket while searching for a friend in a large crowd at a loud concert.)Basically, the brain appreciates the touch of your partner's lips even more when your eyes are closed, since it has fewer outside stimuli to focus on. So, when you close your eyes to prepare for a kiss, you only do so in the name of feeling the kiss, which your brain subconsciously decided was more important than seeing the kiss. It's why you close your eyes during other pleasurable moments, like when you're really feeling a particularly moving song or a Michelin-worthy meal ("mmm, that's amazing!").And, while this one is only a theory, some scientists believe that the closed-eyes kiss may have begun centuries ago, when locking lips was less a romantic move and more a mandatory mating ritual for purely reproductive purposes. Closing eyes was an evolutionary trick to ensure no outside stimuli could distract from the reproductive process.Finally, there's one other reason why we close our eyes in the throes of passion—and it boils down to trust. By closing your eyes, you're letting your partner know that you're able to let go and fully enjoy the moment with them.So, unless your brain has mastered the monk-like art of detecting and interpreting multiple sensory stimuli at the same time (highly unlikely), you'll be keeping your eyes closed for every romantic kiss.
