I’m not the parent commenter, but I’ve heard ‘photophobia’ used to refer to the sort of extreme light sensitivity experienced by migraine sufferers: not a ‘fear of light’ per se, but rather the perception of bright light as an unpleasant or even painful stimulus.
I have a neurological disorder called visual snow syndrome that's the root cause, nobody really understands where it comes from but the current theory is a dysfunction of metabolism in part of the visual cortex. It causes all sorts of weird visual stuff like the eponymous 'tv snow' and other distortions as well as intractable headaches, apparently it has similarities with certain kinds of migraine. As for the photophobia it's quite a difficult sensation to describe but for me its acute form is an unusual sensation that's in the same category as pain without being pain itself - it's like the sensation of looking directly at the sun but with ordinary light sources that don't bother other people. The chronic form is less intense, it basically just makes concentrating in a bright environment exhausting after a while and it trashes my focus, making me headachy and irritable. As a result I never have strong lights on even at night, and I also don't drive in the dark because the glare from the headlights can mess up my vision for minutes at a time which is obviously not safe.
Fluorescent tubes are among the worst offenders for messing with my concentration, though anything with a pronounced 50 Hz flicker or too high a colour temperature isn't great for me. The kind of cheap lights offices traditionally use are particularly bad which is part of why I'm full time WFH now!
