Yes, one drop in each eye is good. It works best if you put the drop in the corner of your eye near your nose, as your tear ducts are there and the eye drops then spread out over the entire eye better. You don't even need to buy Visine. Store brand eye drops are usually cheaper and I don't notice any significant difference in quality. Eye drops are certainly the easiest and quickest way to make your eyes white again.

As for the smell, you can just change your clothes when you're done smoking, and brush your teeth or chew a stick of gum to get it off your breath. If all precautions are taken, no one's the wiser.