I'll try a bit of prophecising here.
Its known that a few modern main battle tanks have all-round camera vision (not upwards or downwards, of course). The F-35 LO strike fighter has a subsystem called DAS, which with six cameras surveils all surroundings, serving as target tracker, missile detector and even (large calibre) muzzle flash detector. Some drones were equipped with a "gorgon stare", nine cameras watching a huge area simultaneously.
All this is sooner or later going to disseminate to the lowest level, the infantryman.
Now keep in mind how tiny and cheap 12+ megapixel cameras on smartphones are already.
Also, keep in mind how tiny and cheap radio-controlled quadcopter drones are.
Finally, keep in mind that every fiberglass communication is essentially a communication by coded laser pulses.
_ _ _ _ _
Combine the ideas and the already available technology and you might end up with an infantryman possessing all-round vision with four cameras mounted on his helmet, and a worn minicomputer interpreting the all-round vision, alerting him of whatever is of interest; muzzle flashed, optics flashes, movements, recognizable shapes of interest, moving drones etc.
The findings would be communicated to the user by stereo sound from earpieces and by a helmet mounted display not much more cumbersome than Google Glass.
He might even have a third set of eyes mounted on a kind of drone that's attached to a tiny backpack and launches from it to hover over his head, communicating with his helmet-mounted sensors by laser pulses and adding ranging by triangulation to the sensing of his "helmet's eyes". Well, this and also the advantage of a bird's field of view.
The whole package may easily weigh less than a kg and cost less than two month's worth of pay.
ETA: About 2 years judging by technology, 10-20 years taking into account the sluggishness of the procurement agencies.
Finally, keep in mind I wrote this blog post under (very much felt) influence of alcohol, and it may be crap. Just as any other claim or idea of some dude on the intertubes. Always be critical, use your own judgement!