Optical metrology methods, apparatuses, and systems for detecting seal integrity. These comprise changing an air pressure inside a chamber to an excitation pressure level when the chamber is placed over a segment of a surface of a structure having one or more seal features and determining whether the integrity of any of the one or more seal features has been compromised by determining, using an optical system, whether any of the one or more seal features have been deformed by the changing of the air pressure.