Patently Apple:

Apple notes in a patent application published today by the U.S. Patent Office that when it comes to authentication using facial recognition, there are potential cases where a user attempting to be authenticated (authorized) by a device cannot be distinguished from another user with closely related facial features.

Twins fool Face ID. Been a thing since the beginning.

Apple’s invention states that “Subepidermal imaging of a face of a user attempting to unlock a device may be used to enhance a facial recognition authentication process”

Subepidermal means below the skin. Interesting.

Subepidermal images of the user may be used to assess subepidermal features such as blood vessels (e.g., veins) when the device is attempting to authenticate the user. The subepidermal features may be compared to templates of subepidermal features for an authorized (e.g., enrolled) user of the device.

Sounds like Apple is offering an extra layer of facial verification for folks with twins or other doppelgängers.

And this last bit, which I found most fascinating:

For example, illuminator 105A and/or illuminator 105B may include an array of light sources such as, but not limited to, VCSELs (vertical-cavity surface-emitting lasers). A first set of light sources in the array may provide illumination at a wavelength for unlock attempt images while a second set of light sources may provide illumination at a wavelength for subepidermal images. The different sets of light sources may be turned on/off separately to allow a specific illumination (e.g., a specific wavelength of illumination) to be provided.

You had me at [Holds up fingers, makes air-quotes] lasers. Cool beans.