http://www.nikonchat.com/fisheye-nikkor-lens/

My goal is blurred? Sorta?
Well from what I've been using my fisheye lens for a while and today I decided to put on my 18 – 55mm Nikon Nikkor VR. When I started taking pictures I realized that everything was a little (but noticeable) blurred. It seems to be blurred at the edges. There is a smug or anything because I took cloth and remove all glass and mirrors. I know it's inside the lens because of my others are fine. * For your information I have provided my glasses in a bag with the caps.
The best thing to do is contact Nikon 1-800-NIKON-UX (1-800-645-6689), you may be under warranty and could be set free.
Nikon 10.5mm f/2.8G ED AF DX Fisheye Nikkor Lens