It really is no joke for some people. Eg, I’m only in my mid-40s but have a neuromuscular disorder and walk with a cane. Even with the cane those two steps would be very tricky for me deal with, without the handrail.

I do the same thing for the same reason as you. Only difference is that when I turn off the light I close the bright-adjusted eye and rely solely on the dark-adjusted eye. Keeping them both open after turning the lights off messes with my head and lack of depth perception isn’t a huge trouble for a quick trip to the bathroom.

On the handful of occasions where I am in the dark for longer, I will open both eyes after a minute or so.