Why are men such visual creatures?!

Jess

I've asked sooo many male friends, from school, work, friends boyfriends and everything!! Every single man is visual whether they are straight or gay, single, taken or married!! They always have to look at other women/men regardless of having a partner, whether id social media or out in person or whatever the case may be! Why? Why are they always like this? Why do they feel the need to always do this? Its so openly disrespectful to us and is so frustrating and aggravating seeing it in your relationship and seeing it and hearing it in your friends, knowing they're all the same and all you can do is either so the same thing or be confident in yourself and say who cares I'm better ... How do you guys get through this without getting upset? Or without showing it?