" Big breasts in a woman and hard loins in a man (that tightly muscular look to the buttocks)—these were naturally important in sexual matchings. But without the eyes, the rest of it could go for nothing. Eyes were essential. You could drown in the right kind of eyes, he had learned, sink right into them and be unaware of what was being done to you until penis was firmly clasped in vagina. He "

― Frank Herbert , Heretics of Dune (Dune, #5)