I'm always using Dark Mode, whether it's in the OS (macOS in my case) or in editors (vim, SubEthaEdit, ...) and suchlike.

Safari has a good view extensions for it too, converting glaring eye-searingly bright pages into something more acceptable and less sun-tan inducing.

For me, I've found I can't stare for long periods at anything bright any more - not just a typical long term software engineer thing - just generally, so it's more relaxing and amenable to concention to use darker themes.

Just my 2c.