Changing the edge width in edit mode I've been watching BlenderGuru's tutorials, and his lines in edit mode are much thicker than mine.

https://youtu.be/9ViVKUiG8ks?t=3m51s

You can see, his lines are solid 2-3 pixel wide, mine are only 1. They also seem to disappear when I zoom in really close. Any fixes?
You can't do that in the current version. It may happen when 2.8 gets released but in the Blender Guru tutorial, he just zoomed the whole view. I suspect since his mouse cursor is still small that he's using the magnifier in Windows. Every operating system (Mac, Linux) has this functionality.