So there has been a bit of discussion about whether or not one wears a mirror & how cars soon may be sold with the ability to project information on the windshield with the wave of a hand. Here's a new piece of tech that fits on glasses, ostensibly for motorcyclists, but I could see Garmin or SRM setting up a connection with their GPS or power meters (or both - wooooo) so that a cyclist's Brikos would reflect a scattering of info back into their eyeball.
Lumus' OE-31 optical engine turns motorcycle helmets, other eyewear into wearable displays -- Engadget
Would you buy one? No looking down away from the road, no vision issues with screens, no chunky piece of plastic lashed to the handlebar. Heck it might even show you what gear your Di2 was in or if there was a car behind you. Or if your wife or husband was calling on your smart phone in your jersey pocket about whether or not you remembered to pick up your daughter/dog/llama from school/kennel/llama day camp.