Many people know that they should take breaks when they're fatigued, but actually recognizing that worn-down state is tricky; it's all too easy to push past the breaking point. If JINS' upcoming Meme smart glasses live up to their billing, though, you'll always know when it's time to relax. The Bluetooth wearable includes both eye and motion sensors that can tell when you're close to nodding off. If it gets to that point, a companion smartphone app will give you a heads-up. The eyewear is useful even when you're fully alert, as it can handle basic fitness duties like step counting and calorie tracking.While the Meme glasses won't ship until spring 2015, JINS will offer a programming kit this fall so that third-party apps can make use of its head tracking skills. Pricing also hasn't been nailed down, but the company plans to release three styles (including the sunglasses you see above) in its native Japan for somewhere between ¥70,000 to ¥100,000, or $685 to $979. There's no word on a US launch, unfortunately, but we're hoping they'll be available for import -- they'd be perfect for dealing with that mid-day slump.