I used to look in a mirror to try to see the sparkle in my eye, – but didn’t see out what people were talking about. Also, apparently my eyes “flash” when I’m upset (my siblings love to see it) but I’ve never been able to figure out what they’re describing.
eclipse, about the pure neshama thing- I think that people who feel things intensely tend to have it more, and who have vivid imaginations. When someone is truly happy, their eyes shine much more. It’s a personality thing.