The blinking thing can shut the light out! (6)
I believe the answer is:
eyelid
'the blinking thing can' is the definition.
The definition and answer can be both body parts as well as being singular nouns.
Maybe there's a link between them I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for eyelid that I've seen before include "Protection for organ of sight" , "Drop it and you cannot see" , "Skin over viewer" , "Object of batting" , "Optical membrane" .)