Require Attention for Face ID
iPhone Device & Theft Protection
Recommended
Keep Require Attention for Face ID turned on unless accessibility needs make it unsuitable.
What this setting does
Require Attention for Face ID adds an additional layer of biometric security by requiring your eyes to be open and looking at the iPhone before Face ID will unlock it. This makes it harder for someone to authenticate with your face when you are not actively looking at the device. Apple specifically notes that requiring attention makes Face ID more secure.
Important notes
This setting is available on iPhones that support Face ID. It does not apply to iPhones that use Touch ID.
Require Attention for Face ID is also an accessibility setting. People who are blind, have low vision, or have other physical or visual limitations may need to turn it off. Apple automatically turns the requirement off if VoiceOver is enabled during the initial setup of the iPhone.
Turning off Require Attention does not turn off Face ID. It changes whether Face ID requires you to be looking directly at the device with your eyes open before authentication succeeds.