Under-Screen Face ID and Screen Protector Compatibility Problem on iPhone 18 Pro

Apple's highly anticipated new flagship iPhone 18 Pro became the first model to shrink the Dynamic Island design and hide the Face ID hardware under the screen. However, initial investigations and tests show that this technological innovation brings with it an unexpected accessory incompatibility. The infrared scanning system stops working when screen protectors with a matte or frosted surface are installed on the device.

How Does Under-Screen Face ID Technology Work?

Apple is noticeably shrinking the large pill-shaped Dynamic Island that has been used for a long time in the iPhone 18 Pro and Pro Max models. While a single circular hole is left for the front camera, the infrared (IR) sensors that power the Face ID system are moved under the OLED panel in the upper left area of ​​the screen.

To implement this system, the pixel density in the relevant part of the screen is consciously reduced. This transparent area with low pixel density allows infrared light to pass through the glass and map the user's face. Thus, biometric verification is provided without a physical sensor notch on the screen.

Why Are Matte and Ghost Screen Protectors a Problem?

The detailed review shared by popular technology publisher Dave Lee (Dave2D) reveals that the mechanism in question is quite sensitive in the choice of screen protector. The rough or micro-textured surface of matte (anti-glare) and privacy-oriented ghost glass protectors causes refraction and scattering of infrared light beams.

Due to this optical distortion, the bottom sensor cannot read the face map correctly and the Face ID unlocking process fails completely.

Since there is no breakage in transparent and smooth tempered glass protectors, infrared light reaches the sensor without any problems and the system works without loss.

Which Screen Protector Should Users Prefer?

This situation, similar to the protective incompatibilities experienced in optical under-screen fingerprint readers on the Android side, appears clearly for the first time in the Apple ecosystem. iPhone 18 Pro and iPhone 18 Pro Max owners should choose completely transparent tempered glass models instead of matte, frosted or privacy filter protectors in order not to compromise biometric security.