Actually, Mason Verger did it to himself in a drug induced state (I believe) ... which Lector helped him with. Revenge for this was Mason's whole purpose for the elaborate plan to get Lector in the "pig pen" in the first place. He wanted Lector to suffer at the tusks of the pigs.
Here is an excerpt from IMDB:
As a result of the publicity surrounding the drug raid, Starling and her past connection to escaped serial killer Hannibal Lecter (Anthony Hopkins) come to the attention of one of Lecter's victims, Mason Verger whom is also a wealthy, sadistic pedophile. Verger, who was left horrifically disfigured and paralyzed by a past encounter with Lecter himself, still seeks revenge for what occurred. He uses his political influence to have Starling assigned to the Lecter case once again in the hope that this will draw Lecter out of hiding.