User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-4388405-20121006181920/@comment-3146930-20121006202624

I'll have to disagree with that comment by Himeyuka. When he woke up by the Wolf House after seeing Hera's true form (I say woke up because in the book, Piper even said she saw him take a breath), it says that his eyes were full of light, glowing completely gold. When the Eidolons take control of a body, the eyes don't glow, they simply change color and look more like Hazel's eyes (if she was taken over, could anyone tell?). Anyway, when Piper was trying to force them out, she said she couldn't believe she had "held hands with...No, she refused to think about it."

But on page 141 (just a few pages before), it is shown that Jason is holding her hand. I think these are two unrelated events and the glowing eyes from TLH is a side effect of seeing the divine form of a god.