Since the iPhone X released in 2018, "Face ID" has been adopted as a biometric authentication technology to confirm that it is a legitimate owner. Using the front TrueDepth (true depth) camera, analyze the face of the person holding the iPhone, collate with the owner's face information registered on the iPhone and if it does not match, unlocking and downloading applications are allowed It will not be. It only takes a glance at the iPhone, so it takes less effort than fingerprint authentication or passcode input.
It is such a Face ID, but it can be unlocked with a sleeping face depending on the setting. When you're sleeping, your family and friends can peek inside the iPhone, so if you want to backgive, you may not be calm. If you are worried, check the setting items.
The setting item is “gaze”. Gaze means that you will not be recognized unless you have a line of sight, that is, with your eyes open. Unless you open your eyes naturally and point your gaze at the iPhone, you will not be authenticated and you will not be able to open your eyes. There is almost no danger of being unlocked while sleeping.
To make face gaze a mandatory condition, open the screen in the order of "Settings" → "Face ID and passcode" (you need to enter a passcode to confirm your identity), and click "Face ID Turn on the "Needs attention" switch (green).
If the “ Face ID … '' switch is off, the time until it is determined that the user is looking at the screen can be omitted, so the authentication speed is improved although it is a very short time of about 1 second . Nevertheless, we recommend that you turn on the "Face ID …" switch unless you have special circumstances, as there is a risk of unlocking while you sleep.