Because no study can find any clinical improvement in sleep quality and duration, I tried with many patients with no effect (I'm a clinical psychologist). So, it's not proven to work practically or anecdotally, only theoretically. But people LOOOOVE to explain why blue wavelengths hit different receptors and glutamate-sensitive cells...

And a note: EMDR works MUCH better than blue-light-reducing therapy. It's just that the theory for WHY it works is insane (integration of memories/thoughts across brain hemispheres is facilitated by moving eyes back and forth). It's just exposure therapy, and the "follow the light" stuff is just structuring the exposure setting. You get the same effect while doing exposure therapy while driving a car.