"Adjustable brightness" refers to the ability to change the level of light or brightness of something, like a screen, lightbulb, or display, to make it brighter or dimmer based on your preference or needs. Full definition
The system utilizes a wide screen with adjustable brightness to ensure both excellent daytime and nighttime visibility. (thekoreancarblog.com)
Other features may include adjustable brightness, and the ability to let you activate music or nature sounds to soothe your little sleeper by remote. (consumerreports.org)
The actual reading experience on a glass screen can be disturbing after a continued period of intensive reading unlike the static black and white screen that emits adjustable brightness. (bbebooksthailand.com)