I am partly blind but can still see. I have legs but only use them for sleeping. What am I?

Why this works

This riddle plays with the unique characteristics of a bat. The phrase "partly blind" refers to the common myth that bats are blind, when in fact they can see, but they rely heavily on echolocation to navigate. The "legs" part is clever, as bats do have legs, but they primarily hang upside down while resting or sleeping, which makes it seem like their legs are not used for movement in the typical sense. Thus, the riddle connects these playful descriptions to reveal the answer: a bat!