Albino Parakeet with darkness around right eye

by Robin
(Ga)

Hi, I have a 4-year-old male albino parakeet. He has darkness around his right eye that looks like it is turning yellow in some places. Is it possible he has a bruise? He has one toy in his cage (a bell) that he plays with all the time. I have noticed him rubbing his face and eyes on the bars of the cage, at times. He does not have any mucous around his cere or eyes. He is eating, drinking and talking as he usually does. Your advice is appreciated.