In response to:
Men admit to being "visually" stimulated...so what happens when that "vision" fades over time...what then?
When you are 30 and she's 45 perhaps the "differences" are not noticeable...but what about when you are 40 an she's 60??
I think it's different when you actually grow with the person. At least it is for me. Even with my cousins, who are now as old as I am, I can still see them as they were when they were younger.
I think the same would be true of a partner. If she was pretty to me when I first met her I would retain that image in my mind and I could still see that youth in her as she aged. My mind would become her fountain of youth.
However, if I met a woman that I already viewed as being "old", then my mind has nothing to revert back to. That's the only image I have to work with.
In fact, I have actually met older people who have shown me pictures of themselves when they were younger and after viewing those pictures I could then look at them and see the younger person behind the wrinkles.
Perhaps it's just me and the way my mind works. I have one hell of an imagination, I only need a seed and my imagination can take care of the rest. Having said that though, if I'm going to start up a brand new relationship I may as well work with a live seed.

When I was in my 20's I think I could have easily hooked up with a 40 year old woman with the full intent of having a permanent relationship with her. I have no clue how it might have worked out in the long term. That would put her at almost 80 today whilst I'm a young-looking 57. I suppose it all depends on how youthful she would appear at that age.
I have an aunt who is 79 and she could easily pass for 50. On the other hand, my mother easily looked 80 when she was 80. My mother died at 90 and if I told you at that time that she was 109 you would not have questioned it at all. So different people age differently. You can't really go by the numbers.