The problem here is biology first and psychology second, combined to be one of the most common issues in many relationships
How about bringing your lady in and sharing this conversation with her?
--- this is for both of you ---
Let's understand the female point of view first. Yes, we are aware that the males in our lives are driven by visuals. That's how we got that male to begin with. To females with insecurity issues, real or imagined, being on guard forevermore is not just impossible, but would take putting blinders on their mate and never letting them out of sight while scrutinizing all media sources.
If this is what she's trying to do and it's got to be incredibly stressful for her so despite her justifications, she really doesn't like doing it - or fearing you'll stray so much that she's become your guard rather than partner.
I could tell you to provide her positive reinforcement about herself and lavish her with attention, but that's not fair to you. A loving relationship is hard work, but it shouldn't be THAT hard.
Now, let's look at the male side of this. Of course you're going to look at women. It's nature. It doesn't mean you're looking for a replacement or that you're seeing something better or that you want to cheat. It's a visual that is very often just a fleeting thing and never thought about again. Meaningless.
Like seeing a beautiful dress in a window - doesn't mean we actually want the dress or would have any use for it in our real life, but it's nice to look at and we walk away.
Like admiring fine china, works of art or even someone else's house - in our own reality we know we're not fine china people, don't really want that Rembrandt in the hallway and what on earth would we do with 5 bedrooms and 5 bathrooms other than live to clean it?
So here's the bot***** *****ne for both of you: Lady is hypervigilant about you glancing or noticing "life" (females outnumber men) - it's impossible to make sure you never see another woman and her confidence should be solid enough that she knows that even if Ms. Universe were to show up at your door, naked, insisting no one will ever know that your choice would be to say 'no thanks, ***** ***** my lady and I'LL know!"
One of the longest lasting marriages I've known, a couple in their 80's, found the wife joking about his 'looking'. He'd been doing it since their 20's and in 60 years never strayed or thought about straying even once. She told me she always knew he looked and most of the time she ignored it; other times she'd call him on it and ask, '...you can't handle ME Barney, what would you do with that?" and they'd have a good laugh.
60 years strong. Barney told me if he missed spotting a hottie, Mary would point her out with something like, "Imagine how crazy her father/boyfriend/husband is every time she leaves the house"
You both should see a counselor in your area for just a few sessions to get to the real root of the issue. Why is your lady so worried? Does she really believe censoring media so you never see an attractive woman is even possible? Or that you should close your eyes throughout life? It will stress you out with worry and make her sick with worry at the same time
I admire you for not judging her and wanting to fix this in a mutually beneficial way.
I can see the both of you, 60 years from now, like Barney and Mary - with barely any memory of how there was some insecurity and worry when you first began