old dog, new tricks

So here's the thing

Living in the city there's always loads of light around if you have to get up in the middle of the night. You don't need to put a light on to, say, get to the bathroom and back.

But sometimes you might find you need a light to maybe find a glass for a drink of water or whatever. Then, of course, your iris muscles contract to narrow your pupils and thus control the light getting through your retina.  And when you put the light off you can't see a thing until your pupil is dilated again. Which means getting back to bed can be a problem.

Then a little while ago I had the idea of keeping one eye shut when I needed to put the light on. The pupil of the shut eye, unexposed to the light, stays wide open. So, once I've turned the light off again, I can open that eye and find my way back to bed in the dark really easily.

Why, for heavens sake, has it taken me 60+ years to work that out?!

And is this common practice.? Has everybody else been doing it, like, forever? Is my vast readership thinking god he's more of a dunce than we thought?

I'll never know, since none of the 5 readers ever leaves a comment. Oh well.