How to Improve Your Android Phone’s Automatic Brightness With Lux
 

Like other smartphones, Android phones use an ambient light sensor to automatically adjust your phone’s display brightness. This often doesn’t work too well.

It’s up to each Android phone’s manufacturer to correctly calibrate the auto-brightness feature, and they generally don’t do an amazing job. The phone may go from too bright to too dim without anything in between.

Lux is a third-party app that allows you to easily calibrate your phone’s brightness sensor, saving you battery power and reducing eye strain if your phone is normally too bright in dark rooms.

http://www.howtogeek.com/168127/how-...ness-with-lux/