Nokia T21 User Manual page 37

Nokia T21 User Guide
Use the Low blue light mode
Blue light is a colour in the visible light spectrum that can be seen by the human eye. Of all the
colours that the human eye perceives (violet, indigo, blue, green, yellow, orange, red), blue
has the shortest wavelength and thus produces a higher amount of energy. Since blue light
passes through your eye's cornea and lens before reaching the retina, it may cause itchy and
red eyes, headaches, blurred vision and poor sleep, for example. To limit and reduce blue light,
the display industry has developed solutions such as the Low blue light mode. To switch on the
Low blue light mode on your tablet, tap Settings > Display > Night Light > Turn on . If you
need to look at your tablet's screen for a long time, take frequent breaks and relax your eyes
by looking at distant objects.
OZO
OZO is a trademark of Nokia Technologies Oy.
© 2022 HMD Global Oy. All rights reserved. 37