with your eyes shut
with (one's) eyes shut
With very little or no difficulty; in a relaxed, carefree, or effortless manner. It took me a little while to get used to this job, but now I could do it with my eyes shut! You should ask Johnny for help—he does this level of math with his eyes shut.
with your eyes shut (or closed)1 without having to make much effort; easily. 2 without considering the possible difficulties or consequences.
1 1994 New Scientist I can knock off pages of eco-babble for the UN with my eyes shut.