Soon after Google launched the Pixel 4, it was discovered that its face unlock mechanism was not particularly secure as it would unlock the device even when the user kept their eyes closed. This meant that anyone could point the Pixel 4 to your face while you were sleeping and unlock it. The company was subjected to a lot of criticism for this oversight especially since the Pixel 4 shipped with dedicated IR sensors at the front which help with face unlock.
Back then, Google promised that it was working on improving the face unlock experience on the Pixel 4 series. Now, the first hint of the company working on enhancing the security of face unlock on the devices has popped up. As reported by Android Police, searching for "eyes" in the Settings menu of the Pixel 4 will bring up a 'Require eyes to be open' option with the description that one's eyes must be open for face unlock to work. The feature is not yet live and tapping on the search result will just take you to the regular face unlock menu.
Presumably, Google is adding final touches to this feature which perhaps explains why it showed up in the Settings menu. Ideally, the feature should have been a part of the second Pixel feature drop rolled out earlier this week. Nonetheless, the company could still add this feature to the Pixel 4 series with the April security patch next month.