it is a myth that dim lighting negatively impacts eyesight long term.
Until you are an adult - you must get outside light (even if it’s overcast winter). On average - luminosity (I hope that’s the term) outside is orders of magnitude above indoors, even when it’s overcast.
Kids without enough light have much bigger risk of shortsightedness. Because eyeball development is related to light.
There was even an article about this on HN couple weeks ago.