Contact lenses for casinos

I've only just spotted this fantastic James Bond-esque story of a group of Italians who were allegedly swindling casinos by reading marked cards with 'special contact lenses'. http://www.dailymail.co.uk/news/article-2049052/Gang-cheats-casino-55k-using-contact-lenses-invisible-ink-marked-cards.html?ITO=1490 Police thought they were using cameras at first but discovered that invisible markings on the back of cards could be read by treated contact lenses. Either that or they were an unfortunate trio of contact lens wearers who just happened to be very good at stud poker.