One who looks on the bright side (8)
I believe the answer is:
optimist
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one who looks on the bright side</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for optimist that I've seen before include "Glass-half-full person" , "glass half-full type?" , "I expect more?" , "Hopeful and confident person" , "One always believes the glass is half-full" .)