able to do (something) with (one's) eyes closed
Capable of doing something with very little or no difficulty, or complete or accomplish something in a relaxed, carefree, or effortless manner. It took me a little while to get used to this job, but now I'm able to do it with my eyes closed! You should ask Johnny for help—he's able to do this level of math with his eyes closed.
able to do something with one's eyes closed
Fig. able to do something very easily, even without having to think about it or look at it. (Always affirmative. Able to can be replaced with can.) It's easy. I can do it with my eyes closed.