I nearly always close my eyes when singing unaccompanied and quite often have my hand cupped over my ear - but then I always think of myself as a singer of songs and certainly not as a "performer" so my first duty is to the song.   I'd rather look worse and sing better than the reverse. I'm probably not people's first choice of what to look at at the best of times and, after all, if I've got my eyes closed, there's no reason why any audience can't do the same if they don't like what they're seeing.

I appreciate if you're going to set yourself up as a performer or an entertainer then image may be important but I'm just someone who simply wants to keep some songs alive and enjoys singing. I do appreciate though that my habits could be annoying to anyone who can't stop themselves from looking at me so - my apologies!