Pixel 4 will get an eye detection feature with an update.
As of now, the face unlocks feature on the Pixel 4 unlocks your device even on closed eyes. This can lead to serious security and privacy issues. Like, anyone can unlock your phone when you are sleeping.
The working of Pixel 4’s face detection is somewhat similar to Apple’s Face ID. However, you have to authenticate the feature that whether to detect eyes or not. Obviously, detecting eyes will make it more secure but slow, on the other hand, turning off the feature will lead to faster login, but less secure.
However, Google says, that the feature does meets the security requirements and will improve with updates every time.
But Google says, whoever is concerned with this feature, should try the lockdown feature on the Pixel. If you take someone else Pixel, try unlocking the phone with their face with closed eyes. The device will initiate a lockdown, and will require Pin or other measures to unlock the phone.
Here is what Google is saying:
We’ve been working on an option for users to require their eyes to be open to unlock the phone, which will be delivered in a software update in the coming months. In the meantime, if any Pixel 4 users are concerned that someone may take their phone and try to unlock it while their eyes are closed, they can activate a security feature that requires a pin, pattern or password for the next unlock. Pixel 4 face unlock meets the security requirements as a strong biometric, and can be used for payments and app authentication, including banking apps. It is resilient against invalid unlock attempts via other means, like with masks.
Source: The Verge