How to Enable and Customise Night Shift and True Tone on Mac to Reduce Eye Strain

Working long hours on a Mac under harsh artificial office lighting or late into the night can cause noticeable ocular fatigue, headaches, and disrupted circadian rhythms. High-energy blue light emitted by modern Liquid Retina and OLED displays signals your brain to stay alert, making it difficult to unwind after work. macOS includes two complementary display technologies engineered to alleviate visual fatigue: True Tone, which dynamically adapts screen colours to ambient room lighting, and Night Shift, which shifts the colour spectrum towards warmer amber tones on a schedule.

Understanding the Difference Between True Tone and Night Shift

While both features modify display colour temperature, they serve distinct ergonomic purposes:

• True Tone: Uses advanced multi-channel ambient light sensors built into MacBook displays and Studio Displays to measure ambient light temperature. It continuously balances screen whites so they appear natural and paper-like under changing daylight and warm indoor lamps.
• Night Shift: Uses geolocation and your Mac’s clock to automatically shift display colours towards the warmer end of the spectrum after sunset. This reduces blue light exposure before bedtime, promoting better sleep quality.

Enabling and Customising True Tone on Mac

True Tone is available on MacBook Pro (2018 or later), MacBook Air (2018 or later), and supported external Apple monitors:

1. Click the Apple menu in the top-left corner and select System Settings.
2. Select Displays in the left sidebar.
3. If multiple monitors are connected, select your built-in display at the top.
4. Locate the setting labelled True Tone and toggle the switch to On.
5. Notice how your screen white point subtly shifts to match the ambient room lighting in real time.

Tip for Creative Professionals: If you perform colour-critical photo editing or video colour grading in DaVinci Resolve or Final Cut Pro, toggle True Tone off during editing sessions to ensure absolute colour calibration accuracy.

Configuring Night Shift Schedules and Colour Warmth

You can set Night Shift to engage automatically each evening:

1. In System Settings > Displays, click the Night Shift button at the bottom right.
2. Click the Schedule dropdown menu and choose your preferred automation method:
   • Sunset to Sunrise: Automatically calculates sunset and sunrise times based on your current location.
   • Custom: Set designated turn-on and turn-off hours (e.g. 9:00 PM to 7:00 AM).
3. Adjust the Colour Temperature slider. Sliding towards More Warm increases soothing amber hues, while sliding towards Less Warm delivers subtler blue light filtering.
4. Click Done to save your configuration.

Quickly Toggling Night Shift and True Tone from Control Centre

To temporarily override or toggle display warmers without opening System Settings:

1. Click the Control Centre icon in the macOS menu bar (the dual sliders icon).
2. Click the Display module.
3. Quick-action buttons for True Tone and Night Shift appear below the brightness slider, allowing you to toggle them on or off with a single click.