I try to sing with my eyes open - but when I sweat, the sweat is acid, and it makes my eyes sting. If I'm nervous, I sweat more. If I'm not playing as I sing, I wipe the sweat out of my eyes as I go along. If I'm playing, I close my eyes because otherwise it hurts. If I've been playing in public frequently I'm less nervous, so I can go four to five songs without shutting my eyes. Two weeks ago I played a two-song floorspot in a club for the first time in three months. Just before I went on someone told me that a man in the audience would give our new band it's first gig if I was good. My eyes were shut before I'd played two lines! (We got the gig)