According to psychologists, the brain cannot focus on two things at once while kissing. This means that if you have to pay attention to the signals received by the eyes while kissing for lottery sambad the brain, this becomes difficult. This interferes with the sensation process of the brain. Which causes the eyes to close.

Emotional cause

People feel close to each other while kissing and want to feel. They want to bring their full support, cooperation and sense of security to the partner. One wants to forget the world by getting lost in the other. Outside objects and noise can distract you if your eyes are open. So people close their eyes while kissing. 

The reason for the room - the advantage of closed eyes is that this way you can kiss each other for a long time. When the whole is open, something will distract you and that moment will be over lottery sambad. Even so You want to experience that moment instead of seeing anything else at that time so close your eyes and let go of its joy.