Passport control looks a little different in Dubai International Airport, the world's busiest for international travel.

That's because the airport debuted a new “smart tunnel” that uses biometric technology, instead of human checks, to allow some air travellers to complete passport control in just 15 seconds.

Passengers register at a kiosk before going through smart gates which use iris recognition to let them through.

Major General Mohammed Ahmed al-Marri, director-general at the General Directorate of Residency and Foreign Affairs, called it the “latest and most unique technology” and says the project has been in development for four years.

For now, it's just business- and first-class passengers who can use the facilities.