They are gnats. Suggestions (from most to least effective)
(1) Kill them with bug spray
(2) wear a scarf or cap to minimize irritation
(3) get an oxygen tank+ breathing apparatus and dive into a pristine unspoilt lake (or puddle). This will help unless the gnats do the same too.
(4) Wear a t-shirt saying "Stop bugging me"
(5) Swear and curse loudly. Assuming the gnats speak English, they'll be off in no time.
Good luck dude!