I was cleaning up my 50mm lens yesterday when I noticed that there appeared to be specks of dust and even a hair inside my lens. I cleaned both sides and it is definitely INSIDE the lens. WTH?? I've only had the lens a year and otherwise it is in perfect condition and looks brand new. How in the hell did it get in there? It appears to be a very fine hair and I haven't done any test pics to see if it shows up in my pictures. Is this something I should be concerned about even if it doesn't show up?