MY HUBBY HAS STRAYING EYES

My husband and i are a young couple, both in our mid- thirties and have two kids, we got married in 2002. He is a generally ok person and is a great father to our two kids. the problem i have with him is he can't keep his eyes off other women when we are out, this happens even when im with him! my hubby's the sort of guy whose eyes stray to a woman's breasts every once in a while when he is talking to her, he can't help himself. It's so embarrassing for me, as the women sometimes notice and get uncomfortable. I'v talked to him about it several times and he always denies it, saying it's all in my head. Most women have a problem with straying pants, my own wahala is straying eyes. Help me out?