Consumer Reports reviews several light therapy bulbs.

The Definity Digital Good Night LED and the Definity Digital Awake & Alert LED are used to help astronauts sleep or remain alert in space, claims Lighting Science, their manufacturer. Lighting Science LEDs were used in NASA ground-based studies, and the manufacturer helped to develop the LED lighting system scheduled for installation in the International Space Station in 2016, according to NASA’s Smith Johnston, M.D. But NASA won’t say which LEDs it actually uses in space.