If you are deaf or hard of hearing, a standard audio chime indicating an incoming notification on a Mac is completely useless. To solve this, Apple includes an accessibility feature that causes the entire screen to flash a bright, inverted colour whenever a system alert occurs.
However, if you have accidentally enabled this feature, or if you bought a second-hand Mac with this setting turned on, the sudden, aggressive flashing of your entire monitor every time you receive an email or press the wrong key can be incredibly jarring and physically uncomfortable.
How to Turn Off the Screen Flash Notification
Because this is a dedicated accessibility feature, it is not located in the standard Notifications or Display settings menus.
- Click the Apple Logo in the top-left corner of your screen.
- Select System Settings from the drop-down menu.
- Scroll down the left-hand sidebar and click on Accessibility.
- In the main window on the right, scroll down to the “Hearing” section and click on Audio.
- Look for the toggle switch labelled: Flash the screen when an alert sound occurs.
- Click the toggle switch to turn it Off.
The change takes effect immediately. The next time you trigger a system error (such as clicking outside a dialogue box) or receive a new iMessage, your Mac will simply play the standard audible ‘bop’ noise, and your screen will remain perfectly calm and stable.