I prefer the darker layout where the light is not necessary. E.g. when preparing a Word Doc i like to see what i get, whereas for file lists or codes this is not necessary. Also in the latter cases, this does not "hurt" my eyes so much. Screen light is still quite agressive. On a reader with passive illumination the light side is perfect.
Dark mode is always the best choice so that you can work deep into the night as a developer and do not want to have any major eye damage :)