As you doubtless know, you can use Face ID to securely and conveniently unlock your iPhone, authorize purchases and payments, and sign in to many third-party apps by simply glancing at your smartphone.
Did you know that you can set up an alternate appearance on the app? You can. In fact, though Apple doesn’t mention it, you can also use this to add another person to Face ID. Let’s look at how to do this.
If you didn’t set up Face ID when you first set up your iPhone, go to Settings > Face ID & Passcode > Set up Face ID, then follow the onscreen instructions.
To set up an additional appearance for Face ID to recognize, go to Settings > Face ID & Passcode > Set Up an Alternate Appearance, then follow the onscreen instructions.
If you have physical limitations, you can tap Accessibility Options during Face ID set up. When you do this, setting up facial recognition doesn’t require the full range of head motion. Using Face ID is still secure, but it requires more consistency in how you look at iPhone.
Face ID also has an accessibility feature you can use if you’re blind or have low vision. If you don’t want Face ID to require that you look at iPhone with your eyes open, go to Settings > Accessibility, then turn off Require Attention for Face ID. This feature is automatically turned off if you turn on VoiceOver when you first set up iPhone.
(This how-to is based on my experiences and info on Apple’s support pages.)