What is the small circular spot above ipad screen?

I have an Apple iPad 32GB 4.2.1. If you have good eye sight and look very closely at the top-center of an iPad (above the actual screen, in the "margin" if you will) there is a small perfectly circular and centered spot. My knowledge of computers and stuff tells me that it should be a camera, but my knowledge of the iPad 2 tells me that is not the case. So, what is it? Thank you.













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