Q:

Who was the man with one sunglasses lens in Casino Royale? 

In Casino Royale (2006), the main villain is named Le Chiffre.  His left eye has been injured somehow, which causes him to bleed from his tear duct on that side. 

The best explanation comes from Le Chiffre himself:

Weeping blood comes merely from a derangement of the tear duct, my dear General.  Nothing sinister. 

Later in the movie, there is a mysterious character who wears glasses with a single shaded lens over the left eye.  

Is this meant to be Le Chiffe? 

 We saw Mr. White shoot Le Chiffre in the head and save Bond. ( or did we?) 

It seems like an unlikely coincidence that this mysterious man and Le Chiffre both have something wrong with the same eye. 
Is it just a coincidence? 

A:

No he is another character called Adolph Gettler

Adolph Gettler was a fictional operative of the criminal organization Quantum.  The villain was based on the literary character who first appeared in the 1953 Ian Fleming novel Casino Royale and was portrayed by German actor Richard Sammel in its 2006 James Bond film adaptation of the same name.  The character later appeared in the 2008 video game Quantum of Solace, which incorporated scenes from the 2006 film.