able to do with eyes closed

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.
See also: able, closed, eye
Farlex Dictionary of Idioms.

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.
See also: able, closed, eye
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • able to do (something) with (one's) eyes closed
  • able to do blindfolded
  • able to (do something) blindfolded
  • able to (do something) with (one's) eyes closed
  • able to do (something) standing on (one's) head
  • a fast talker
  • a/the feel of (something)
  • (I) wouldn't (do something) if I were you
  • all righty
  • a straw will show which way the wind blows