Q: Volume icon is disfigured. Any solutions to this problem?

I logged into my macbook pro like I do everyday and when I clicked on the volume key the volume icon appeared to have weird lines on both the top and the bottom. It has happened to one of my friends a few months ago and she never knew how to fix it and when the same thing happened to me today, I had to find solutions to this problem. I have not found any solutions to this problem whatsoever. Please help me fix this as I do not have an apple store nearby and I have been searching around the internet all day. Thanks!