A pair of glasses, with lenses as thick as the bottoms of glass Coca-Cola bottles. It means the wearer is blind as a bat without them. Whenever I'd go see Woody Shaw play, he'd invariably have to be led to the stage by somebody - the venue would usually be too dark for him to navigate alone. Sometimes, while somebody else was soloing, he'd be off to the side of the stage doing tai chi; I was always afraid he'd stumble and hurt himself there in the shadows. Blind as a bat.