Samsung
Turn Open-Eyes Requirement for Face Recognition On or Off auf Samsung
Face recognition on Samsung phones can unlock the device even while your eyes are shut, unless the open-eyes requirement is active. This setting forces the camera to detect open eyes before it accepts a match, which closes an obvious security gap: anyone could otherwise unlock your phone while you are asleep or unconscious just by holding it up to your face.
On most Samsung devices this option is enabled by default. If you notice your phone unlocking too easily, or if the feature feels too strict for your daily use, you can change it manually.
Where to find the setting
Open Settings ➔ Biometrics and security ➔ Face recognition. Enter your current Pattern, PIN, or Password to confirm your identity, then toggle Require open eyes on or off.
Turning it off speeds up unlocking in low light or when you are wearing certain glasses, but it lowers the security bar. Turning it on adds a check but can fail more often for people with droopy eyelids, some medical conditions, or heavy makeup around the eyes.
If Face recognition keeps failing entirely, this toggle will not help. That points to a different issue, such as poor lighting, a dirty front camera, or a face model that needs to be re-registered.