Masking an image

I'm trying to create a specific 2d effect (using 2d toolkit) and I need some assistance. The effect i'm looking to achieve is similar to a magnifying glass. I would have a static blurry image on the screen, then when the magnifying glass image overlays, the blurry image disapears, revealing the game play below.

tl;dr Trying to use a circle image as a mask to create a cutout effect

Is this possible in unity?