I can't personally support light modes in my own software because I can't use/test them, but I'd still add an untested one and fix bug reports about it.

I'm just curious about what people mean when they talk about astigmatism in this context, because the term is usually thrown around without qualifications (plain "astigmatism" as opposed to "irregular astigmatism" or "uncorrectable astigmatism"). So I'm curious about the astigmatism of people for whom dark mode on glowing devices is a problem. Is it typically extremely severe? Is it typically uncorrectable? Is it that people's glasses or contacts are often subtly wrong/outdated? Are many astigmatics not myopic or presbyopic enough to wear glasses all the time anyway? Astigmatism is a broad category and I'm curious about the specific impairments people who avoid dark mode have, in part because I have astigmatism and nonetheless prefer (require, really) dark mode because of other vision problems.