I had an odd looking vireo in the same location around noon on Saturday. Grey head, faint but apparent white spectacles, large black eye, no trace of a white iris, and an olive back. Very active, it was feeding at mid height in the poplars. Tried to get a photo, but the bird was so active, almost warblerlike, that it was hard to zoom in on it. Looked more like a drab Bell's than a White-eye--not a lot of yellow in the flanks, and the specs were definitely white, not yellow. I'm very familiar with Blue-headed, Warbling, and Red-eyed--it was none of those, and it lacked the eyeline that you find in a Philadelphia. Can't say for sure what it was, but anyone in the area may want to keep an eye open.