Craig wears the silver ones MUCH more than the tortoise ones in the movie...I counted at least three scenes where the metal ones are worn. They are amazingly comfortable to wear and stylishly classic.
And this is from the Persol web site:
Persol continues its long and successful cinema heritage dressing the gaze of James Bond in the latest 007 movie “Casino Royale”
November 2006 - Persol is once again dressing the gaze of James Bond in the latest 007 movie “Casino Royale”
November 2006 - Persol is once again dressing the gaze of James Bond, the legendary British secret agent, in the new 007 movie “CASINO ROYALE”. James Bond perfectly represents Persol image and values: fashionable, stylish, yet sophisticated.
In Casino Royale, James Bond wears two pair of Persol frames during the film. At the start of the plot, Bond wears a Persol metal frame: Persol 2244. In the second part of the story after experiencing a number of adventures, James changes to Persol style 2720 (turtle frame and green lenses, color code 24/31).
Cinema has always been in PersolÂ’s DNA. Since the 1960s, Persol models have featured many times in some of the keynote films of Italian cinema. Persol eyewear has been the personal choice of many unforgettable artists of the silver screen and international celebrities. The strong bond with the world of cinema has remained constant over time. Today, it takes the form of the shades chosen by James Bond and this is happening actually for the second time after Persol appeared in the last film DIE ANOTHER DAY (2002).