The intervention that most advocate for is shifting kids’ breaks to be outdoors during peak sun hours. This is free ($0.) You get 100k lux, high CRI, flicker free light with no power or setup requirements. You also get birds, trees, buildings etc in the distance as “infinity” focus targets, also for free. (Reminder that “infinity” is actually fairly close!) This approach is also proven to improve myopia rates.

Custom water-cooled ultra-powerful indoor lighting setup as suggested by sibling comment: $30k/small room (far focus not included)