Blinding an Irish Woman

Alright, listen up, you big lug! This joke is playing on a really old, unbased stereotype that Irish people are big drinkers, specifically of whiskey like Scotch. The 'blind' part is a double whammy, see? It means she'd be literally 'blind' to everything else because she's so focused on the bottle, AND it implies she might get so drunk she can't see straight, making her 'blind' in a different way. You probably think this is super clever, don't ya? But it's just a tired stereotype, you slowpoke. Go read a book, or at least a label on a bottle.