Consider doing more than squinting and using your hand, especially when the sun is on the horizon, or you might end up with Pterygiums like I have. They are growths on your eye balls thought to be caused by wind, sun and sand. Normally, I don't even know they are there, but when they get irritated, it feels like a sty (sp) but it's not on your lid, it's on the eyeball. Kind of creepy.
In any event, I'm more careful now, of course. I have seaspecs which aren't bad, but I have a hard time getting used to them. Plus, they make you look kind of like a fly. A full brimmed canvas hat with a drawstring that goes under your chin is what I've found to be the best. Used for morning sessions on the east coast, and evening sessions on the west.