Consistent daytime eye exposure to photons and ultraviolet light without sunglasses helps regulate appetite by stimulating MSH.

“So the takeaway tool from this, is make sure you're getting enough light not just in the morning, but throughout the day. And yes, it has to be light to your eyes. And blasting your eyes with sunlight or artificial light to the point where it's damaging or painful, won't accelerate or improve this process. It's about getting photons, ultraviolet light to the eyes consistently throughout the day. That's best accomplished by not wearing sunglasses provided you can do that safely.”