The Crave sunglasses by POC are designed with mountain bikers in mind. This model is very similar to the DO Blade glasses, but with lens tinting that makes it easy to see the trail clearly with no shadow. The frame and lens combinations are customizable and easily interchangeable, allowing you to stylize them however you want, provided you own or purchase other parts. These glasses are designed specifically to fit perfectly and comfortable beneath POC helmets, but it seems like they fit that way with most any helmet on the market.
The mono-lens design deviates from the typical dual lens design, and many users claim that this design increases both comfort and visibility. The glasses are very lightweight, but stay on your face easily (no matter how sweaty you get) thanks to the rubber nose piece and snug yet flexible arms. This makes it so that you have to adjust your glasses less often, keeping the lenses clear from oil, dirt, or mud. User and vendor reviews of these glasses all point to their great quality and high level of comfort. The only glaring negative of this product is its price tag, making for a fairly expensive set of glasses. Though the price is high, you would certainly get a high payoff to match.
Overall, the Crave sunglasses will serve an enthusiast mountain bike rider well, giving you a pair of glasses that you can put on and not have to fuss with during your ride.