Red-eyed Vireo

Back on 18 June 2010, I posted a photo of an adult Red-eyed Vireo showing its red eye.  I promised to look for an immature bird.  I caught this one last Thursday--a brown-eyed Red-eyed Vireo.  Age is told by eye color.  Perhaps the brown eyes reduce aggression from red-eyed adults, indicate breeding condition or readiness, or perhaps just identify young vireos.