New York City - A correction officer has been disciplined for dozing on the job after a colleague snapped a picture of her asleep while on post at a Rikers Island infirmary, officials said yesterday.

A clearly conked-out Nadja Green is leaning in a chair with her head back, arms folded, eyes closed and mouth open.

But even more alarming is an amused inmate seen hovering above her, mere inches from a set of keys that hangs from her belt.

The picture was circulated around the department, and a source e-mailed it to The Post.