Organs of sight (4)
I believe the answer is:
eyes
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">organs of sight</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eyes that I've seen before include "They see and" , "Optical organs" , "Organs of vision" , "Narrowly observes" , "They have pupils" .)