I always wear this ALBA quartz watch when I sleep.
That's because my automatic watch stopped, and I overslept before.
I changed the original nylon strap to this expansion wrist watch band.
The adjustable strap can be loosened, it's easy to put on your wrist, and you can't feel it, so it won't bother you while you sleep.
It's also light since it's made from titanium.
The number index is really easy to see, the luminous shines brightly, and can be easily seen by even someone who is shortsighted like me.
Even though it has absolutely nothing to do with sleeping, it also has 20bar water resistance.
It is expected to cost 9800 yen ($90) here in Japan