I shoot a good bit in low light and darkness. Don't recall the muzzle flash being a problem.
I do the eyes closed shooting thing once in a while.
(I have a home range so I can do such as this in complete safety, don't try this at your local range
)
The results can be surprising.
For instance.
My new CZ 40P pointed so naturally I tried it with my eyes closed.
I wanted to see what would happen when shooting at the BG with eyes closed.
From up close I used a Taurus PT99, which I hardly ever shoot.
Most shots were single shots, with a couple double taps thrown in. I missed 3 times.
I've often said that a decent shooter could pass the Texas Concealed Carry qualification with their eyes closed.
So I decided to "put my money where my mouth is".
The qualification is timed fire at 3-7 and 15 yards. 250 points total, 174 to qualify.
Before each shot or string of shots I started with the gun pointed down and my eyes closed and kept my eyes closed until finished firing.
Without shooting for the 50 points at 15 yards I still passed by 4 points.