Just be sure they're sporty--with some wrap around. I got really "smart" last year and decided I needed some prescription sunglasses with a bifocal in them so that I could read the map on a cycling trip. Well, they had pretty big lenses--older pair of frames that were on sale. I could read the maps alright, but when I was going downhill, they were so huge that the wind got behind the lenses and I cried all the way down the hills--couldn't see a d@#n thing thru the tears! Well, they're good for being on a cruise and reading in the sun! I just take somebody with me to read maps.