Apple has filed for a patent (number 20200279541) involving technology that would keep you from experiencing “luminescence shock” when using your iPhone or Apple Watch.
Luminescence shock occurs when a device is turned on in a dark environment and the brightness of the display temporarily impairs the user’s vision. Not only is it bad for your eyes, but a large display illuminated to full brightness will exhaust a battery quickly.
Apple’s idea is for a luminescence shock avoidance algorithm that selectively limits the brightness level of an iPhone or Apple Watch when the display device is activated in a dark environment to prevent the temporary vision impairment that can occur when a display device is activated in a dark environment.
The algorithm receives the state of the display (e.g. on or in standby mode), and can optionally receive an ambient lighting value from an ambient light sensor and a user-selectable manual brightness adjustment setting to determine whether luminescence shock avoidance should even be triggered, and if it is triggered, how much should the brightness level of the display be limited.