Biometric eye scanners installed in some of the busiest airports in the UK have been used by 2 million people since their arrival in 2006.
Nicknamed IRIS (Iris Recognition Immigration System) the scanners can be found in Heathrow, Manchester, Gatwick and Birmingham airports and are meant to aid in immigration security checks.
Making it difficult for criminals
The Home Office revealed the statistic this week, alongside the news that 300,000 people have signed up to use the IRIS system since it was installed.
The reason they have signed up is that using the biometric scans is meant to cut down queuing when arriving back in the UK.
Speaking about the eye checkpoints, Border and Immigration Minister Phil Woolas said: "The IRIS system is a prime example of how the UK's strong new Border Force is using the latest technology to speed up travel for legitimate passengers while making it more difficult for criminals and illegal immigrants to get into the country."