Blue-light exposure has been identified as causing sleep depredation.
Reducing blue-light exposure protects your eyes and provides the best nighttime reading experience. Some devices like the Kobo Aura ONE, Kobo Aura H2O edition 2, Tolino Vision 4HD and some models of the Apple iPad have an automatic setting that mimics the sun’s natural progression, emitting the optimal brightness and hue based on the time of day. Blue Shade is an exclusive Fire OS “Bellini” feature that works behind the scenes to automatically adjust and optimize the backlight for a more comfortable nighttime reading experience.
There are also third-party programs for Android and desktop OSes that will filter blue light automatically based on time-of-day location settings. These include Twilight, Redshift, and f.lux.
 more hardware
- DASUNG is concerned with this issue.