Anecdotally, I designed and built a simple 'LED on a stick' to emit 660nm or 850nm red light at levels that cause eye damage and found it cuts wound healing time roughly in half.
Driven at 1 amp, ~2 inches from skin, ~5 minutes, twice daily. 660nm seemed to work better. Note that 850nm light is not visible and exceptionally dangerous. You will burn your eyes by looking at anything the invisible light is bouncing off of.
