Watches and wearable things are just the tip there. The issues with implants is that they are 100% against the Hippocratic oath. No doctor would ever do one if you are healthy. Implants are a long way off, and wearable enhancers may ease the road to them, however a new ethical system for doctors, or an extension of doctors without such oaths, would be required. Think about it for more than 30 minutes, it gets heeby jeeby real quick.