Do guys use peripheral vision to check girls out

sorry if I spelled peripheral wrong but whatever I've noticed on quite a few occasions guys trying to look at me from the side without actually staring at my face. They will either check me out from the corner of the eye or turn around to the side pretending to look at something at the side like a paper on a bulletein board and I just wanted to know why do guys do that?How will they get a good profile of the girl if they only try to see her from the side?
Do guys use peripheral vision to check girls out
Post Opinion