mine didn't exactly go blurry, but everything shook so much it looked like it //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
jemorgan85 told me that the resonant freq of your eyes is 8 hz. So if you can play an 8 hz tone, you would be going freakin blurry and it wouldn't hurt your ears.