I have found most hardware stores carry Polycarbonate 100% UVA sun glasses (wrap around style) for under 6 dollars a pair, with a little care they will last two seasons and I use a 3/4 helmet. They are shatter proof, dark, also come in blue or yellow, thin and light yet strong enough for the construction trade. They work very well on a bike and are as safe as any pair you can buy.
Down side--------- Not the best looking pair of glasses you could buy.
Down side--------- Not the best looking pair of glasses you could buy.
