I wish I could have gotten a pciture of it, and I cannot get her to do it again...
One of our newest two kittens, Sissy, a long haired all black female, loves to have her ears scratched...I think it goes back to when she had earmites and I would give her the drops then work her ears with the swab...she seemed to love that whereas mosts cats struggle...
Anyways, I was holding her in the crook of my arm, like a baby, and scratching just at the inside base of her ears...her head fell back, and the third eyelid came out and completely covered her eyes...there were these two completely white eyelids within the black face...and she was just purrrrrring away...
When I stopped, she folded back that third eyelid, looked up to find my hand and pulled it back to her ears for more scratching...