I don’t think he’s albino: his quills are banded - albino is white. So there’s a possibility that one eye was already darker and just not noticed.
but if it seems irritating to him, the only way to get an answer would be through a vet having him assessed. Could be as simple as dust irritated his eye if you use any loose substrate, or it could be something behind his eye that you can’t see (one example; tumour).