True, but only by people who liked Lily. Remus, Sirius, Dumbledore at times... We were led to believe that Snape didn't like Lily, so he wouldn't really care about that detail, would he? Pre-DH, I don't think he would've called it 'Lily's eyes'... maybe 'Evans' or 'his mothers'. But I take it then you didn't do it on purpose. :P