This is why the notch isn't included in screen protectors.
FaceID uses an illuminator based on an IR laser diode similar to what CD players use. The beam is split into thousands of tiny beams to project an array of dots on your face. The beams are easily distorted by any kind of dirt or substance on the surface of the screen covering the projector lens.
Just as your camera's lens must be clean or your shots at night with bright lights (i.e. streetlights) will show tails or streaks. The laser dots won't be dots any more. This causes the reader to no longer identify your face. It's also important to make sure the screen is clean when capturing a faceID.
If this area of the screen becomes permanently scratched it could certainly mar the accuracy and ability for captures and recognition as well.
This overall reduction in accuracy could
possibly be the reason why a mother's son was able to unlock her phone.
https://www.wired.com/story/10-year-...hers-iphone-x/
As we say, more testing needed.
