Not to burst your bubble, but the usual eye-line is the back wall of the theatre - or higher, if you're playing a auditorium with a balcony. It's to make sure everyone can see your face. I can promise that he saw you, though, and would have noticed, and been sad, if you'd left. Keeping an audience engaged is the whole deal, and if standing-room patrons stick around you know you're getting it done.