Currently, iPhones are unable to differentiate between smudges that block light to the phone’s sensors and other reasons why the light might be blocked, such as when the user is talking on the phone and it is held to the user’s ear. Smudges to the phone can dim the screen accidentally, mimicking the dimming that occurs during a phone call.

The new system would be able to identify different types of smudges and make sure that they don’t interfere with the normal lighting of a phone.