ROTFLMAO! Thanks for making my day....

I started bike commuting about a month and a half ago and I've had trouble feeling comfortable that I am actually seeing (or not seeing) cars far behind me. This is not so important in slower traffic, but on the 40 mph roads I feel a little hesitant to change lanes. I wear glasses and unless the car has DRL, its hard to confirm the lane is safe as many colors don't stand out well for me against the road. A mirror is definitely on my list.