How to reduce the intensity of blue light in macOS 11 Big S

To reduce the effects of blue light, activate Night Shift on your computer.  Night Shift reduces the amount of blue light screens emits by increasing warmer, amber tones.

In this article

How to turn Night Shift on manually
How to schedule Night Shift
How to adjust the colour temperature for when Night Shift is active

How to turn Night Shift on manually

1. Select the Apple icon  in the top left corner of the screen.
2. Select System Preferences from the menu.
   
3. In the System Preferences window, select Display.
   
4. On the display screen, select the Night Shift tab.
   
5. On the Night Shift screen, tick the checkbox for Manual.
   
6. Night Shift will turn on until the next morning.
7. When you have finished, click the Close (red) button in the top left corner of the System Preferences window.

How to schedule Night Shift

You can schedule Night Shift to turn on and off automatically depending on the time of day. You can set Night Shift to turn on at sunset and turn off at sunrise, or you can create a custom schedule with times to suit you.

1. Select the Apple icon  in the top left corner of the screen.
2. Select System Preferences from the menu.
   
3. In the System Preferences window, select Display.
   
4. On the display screen, select the Night Shift tab.
   
5. On the Night Shift screen, select the drop-down menu for Schedule.
   
6. Choose from:
   • Custom
   • Sunset to Sunrise
     
7. If you choose Custom, set the times you would like Night Shift to turn on and off.
   
8. When you have finished, click the Close (red) button in the top left corner of the System Preferences window.

How to adjust the colour temperature for when Night Shift is active

1. Select the Apple icon  in the top left corner of the screen.
2. Select System Preferences from the menu.
   
3. In the System Preferences window, select Display.
   
4. On the display screen, select the Night Shift tab.
   
5. On the Night Shift screen, adjust the slider for Colour Temperature. Adjusting the slider to the left (Less Warm) will allow more blue light when Night Shift is active. Adjusting the slider to the left (More Warm) will allow less blue light, making the screen colours appear yellower when Night Shift is active.
   
6. When you have finished, click the Close (red) button in the top left corner of the System Preferences window.

Note: If this does not work, it could be because someone else manages your computer settings (an IT department or administrator). If this is the case, you will need to contact them to access these settings or for further help.