Bose is already shipping its Frames audio AR sunglasses, but if you're looking for a pair of sportier spectacles that have integrated wireless Bluetooth audio, there's also the new OptiShokz Revvez from AfterShokz, which I previewed back in January. They're now available for preorder via an Indiegogo campaign.

Designed to allow cyclists, runners, hikers, golfers, skiers and others to listen to audio and make calls on the go while maintaining "ambient sound awareness," the OptiShokz Revvez use bone-conduction technology to pipe sound into your ears through the cartilage behind your ear (it's not as weird as it seems).

There are five lens options -- the lenses are interchangeable -- and early-bird pricing has been set at $99 or a 50 percent discount off the Revvez' list price of $199. Alas, there's no prescription lens option, but you can get a polarized lens for $15 more.

They're due to ship around June, although delays are always possible. While AfterShokz is an established company and the product should ship, as with any crowdfunded campaign, we always note there's a chance it won't. 

I've been playing around with an early sample for the last few weeks and it's an interesting product. They don't quite have the look and feel of a pair of premium sunglasses, but they seem pretty durable and come with a decent carrying case. 

Bone-conduction headphones, which typically transmit sound through your cheekbones, don't sound as good as traditional headphones, but they've improved a lot over the years, and AfterShokz makes arguably the best bone-conduction headphones.

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With these glasses, the end of the arm -- where the bone-conduction element is located -- is bendable. You fold the end down onto the back of your ear, which helps keep the headphones securely in place on your head. It's kind of like have a little clamp on each arm of the sunglasses. 

The Revvez don't sound as good as the Bose Frames, which have actual speakers integrated into their arms, but do offer slightly better battery life (around 6 hours). They do sound OK -- there's just enough bass and volume -- and they deliver a kind of background music listening experience because you perceive the sound in your ears but it also seems a little outside your head. Crank the volume to the highest level and you will feel a tickling vibration on the back of your ear. So about 75 percent volume is where you'll want to be.

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These are not headphones for critical listeners. But they sound good enough and will be appealing to runners and bikers who want to hear traffic around them for safety reasons. Also, for those entering race events that prohibit the use of headphones that block your ears, these audio sunglasses would be a good option. I don't know if I'd pay $180 for them, but $99 is a lot more tempting. 

Here are the OptiShokz Revvez' key features, according to OptiShokz:

• First sunglasses with transducers positioned to transmit sound through the cartilage behind your ear             
• Bendable two-position titanium temple arms
• Water and sweat resistant (IP55 certified)
  
• Each pair includes three interchangeable silicone rubber nose pads to ensure a comfortable fit
• Five lenses to choose from: Polarized grey, REVO blue, gradient grey, transparent and bright yellow
• Lenses are interchangeable and molded in Teijin polycarbonate (glasses come with your choice of one lens, and additional lenses are sold separately)
• Open design leaves ears open and allows you to hear the outside world while listening to audio
• 6-hour battery life
  
• You can charge fully in less than 2 hours
  
• Bluetooth 4.2
• Dual noise-canceling microphones eliminate external noise while enhancing speech volume for phone calls
• Price: $199, with early-bird pricing of $99 (no word on international pricing)
• Protective carrying case included
• Available around June, though no ship exact date has been confirmed