Sparkle, shimmer (5)
I believe the answer is:
gleam
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sparkle</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">shimmer</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for gleam that I've seen before include "Glisten" , "Brightness" , "Shine brightly" , "Beam of soft light, comes and goes" , "Look in the eye" .)