The lenses are nice because they offer 100% UV protection and are comprised of TR90 nylon. They also offer excellent clarity. They seem durable too. We won't be testing out the concept by dropping cement blocks onto them. But, they seem tough and they'll have to be to survive our usage.
i-Design ID1010 Screw Free 62mm Rectangular Sunglasses list for $149.99. They sell for $59.99. The link to buy is just below this sentence.
Vital Link: Amazon