Unable to see screen (5)
I believe the answer is:
blind
I believe this is a double definition.
'unable to see' is the first definition.
(I've seen this before)
'screen' is the second definition.
(synonyms)
(Other definitions for blind that I've seen before include "Window screen on a roller" , "Sightless" , "deception" , "Unable to observe" , "relying on instruments" .)