AR has been done for ages with head mounted displays (lightweight is mostly a factor of time+money the AR rigs or 80's were not light but the ones from 2000's are)
Google "Wearable Computing", "Professor Steve Mann", "MIT's Media Lab". http://www.eyetap.org/
Google "Wearable Computing", "Professor Steve Mann", "MIT's Media Lab". http://www.eyetap.org/