Viewing sunlight through a window is 50 times less effective than being outside without sunglasses for timing the circadian clock early in the day.

“he tells me that it's 50 times less effective to view this sunlight through a window, through a car windshield, or through the side window of a car than it is to just get outside with no sunglasses and view light early in the day.”

“And he tells me that it's 50 times less effective to view this sunlight through a window, through a car windshield or through a side window of a car than it is to just get outside with no sunglasses and view light early in the day.”

“Setting your circadian clock with sunlight coming through a window is going to take 50 to 100 times longer.”

“It doesn't scale that way just because the biology doesn't work that way.”