Gymble- two issues with your post:
Permanent nights are not an answer. They do away with the transition stupids, but there's still adverse effects for a diurnal animal (us) functioning at night, and it shows in many facets of health. I've not seen a study that accounts for personality in selecting night work, so that may be a factor, or a study that weighs the adverse effects of transitioning against continued nights. So, we all take our turn in the barrel. My point is that there are better ways to transition to nights than a 24 hour flip, the industry standard.
Next, even optimally swapped to nights, I'm still optically diurnal. The military have proven the advantages of aided vision at night, and it's far cheaper than what we're doing now. I work for the single biggest EMS operator in the US, and any single fatal night crash we've had is approximately the cost of equipping our entire fleet. The illusion is that the next one (fatal crash at night) somehow won't happen, and we'll just keeping doing the same thing, LA LA, LA LA, LA LA...
I'll repeat a fact- the military have proven the benefit of aided night vision. Been there and done that- Unaided, back in the day, and saw the same accident rate and profile of helo EMS now, unaided.