Depends on what you mean by "sexy"...
By my definition a woman is "sexier" if she is old enough to have accomplished something in life, smart enough to be able to have accomplished something in life, and a successful enough that she can say she has accomplished something in life. I've meet women who were "sexy" that were well into their 50's. Yes, they were also attractive, but to me sexy is more than that...
If we are limiting it to the physical, but still talking about "sexy" as a state of mind (for both parties) as oppossed to in the porn sense of the word....somewhat more mature and womanly of figure is more sexy to me. For example...went to the bank today...got out of my car...at the same moment a women half way between me and the bank also got out of her car. What an ass....now, frankly, it wasn't perfect (it was a little bit flat), but she was relatively slim, but yet she had hips...actual hips...and thighs...not too big, but big enough to look meaty and heathy...and she was wearing these tight ass lycra jeans that left nothing to the imagination, yet somehow looked tasteful.
Much to my delight she was heading to the bank as well, so I got a chance to follow that ass all the way across the parking lot, into the lobby, then stand behind it in line. Even in the parking lot I could tell she was not a spring chicken...not some 19 yo Paris Hilton wanna be...but when I was standing behind her I finally got a close look. She was a lovely Latina WOMAN...probably mid 30's. Her skin was not flawless, but her features were...she had the sort of beauty that with expert makeup would be breathtaking. And her body...it wasn't the body of a 19yo bikini model, but it was wonderful...a WOMAN's body.
She could tell I was staring...she smiled a bit awkwardly, then did her best to ignore me, while I did my best to hide boring gaze....but standing behind her in that line was ten minutes well spent.
So...what is sexy? It is the difference between seeing a woman and thinking I'd like to see her naked with her on her knees with my cock in her mouth...and seeing a woman and thinking you'd want to make love to her (not fuck...make love...wrapped in sheets for modesty sake while she attemptd to hide her "body flaws".) Sexy is when you see a woman and the first thing you think of isn't "I'd like to fuck her", its "I'd like to talk to her...I'd like to get to know her better"
By this definition, yeah...eyes and maturity count for A LOT...
Of course, it doesn't hurt to have a juicy round ass....LOL