To automatically set the brightness to the preset low setting, press Option, and then press Right Shift.
Display and appearance
Adjusting the brightness
Depending on the lighting conditions in which you’re using your smartphone, you may need to adjust the brightness of the screen.
1.Press Option 
, and then press Backlight 
.
2.Press Left 
and Right 
to adjust the brightness.
3.Select Done.
Changing the screen text size
You can change the screen font in Calendar, Contacts, Memos, Messaging, and Tasks. The font styles may vary between applications.
1.Open the application in which you want to change the font.
2.Open the menus 
.
3.Select Options, and then select Font.
4.Select a font style.