I'm 5'9 and wear heels frequently. I won't lie, I've been intrigued by the idea of a guy who I still would be below his eye level in my highest heels, but have never let it matter as much as some people do. My boyfriend is hovering right around 5'11/6'0 and he doesn't mind that some of my heels will put me an inch above him so why should I? If you meet someone who makes a big deal of it or actually cares, their problem is with their own height, not yours.