Is Charlie Sick or Old?

We've had Charlie only 2 and a half years but this evening we discovered what looks like a cataract on one of his eyes. They live to be 2 to 4 years old but we have no way of knowing how old he was when we got him, only that he wasn't fully grown since he got bigger after we got him (either that or he was wasn't thriving in his previous home at WalMart). Hopefully it's only a bacterial/ick thing and it will go away in a week with treatment.