I've never owned super expensive sunglasses, though I've owned many cheap and medium priced ones. I've never once owned a pair that if I wore on the course I felt 100% about my depth perception and focus on the ball. That's why I never wear them on the course, despite the fact that I live in SoCal and wear them pretty much 100% of the time I'm outside off the course. It's one of the reasons I've taken to wearing a sort of old man style wide brimmed straw hat on the course. Luckily oldster style hip is sort of in these days (though its moment seems to have passed a bit), so... Wide brim hat!
I'm with you on that @mdl, I'm not crazy about sunglasses for golf and have always felt that my depth perception is off a little when wearing them.