Apertures in the eyes (6)
I believe the answer is:
pupils
'apertures in the eyes' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for pupils that I've seen before include "Scholastics in the eye" , "Students and eye apertures" , "Students' eye parts" , "Apertures in the eyes" , "Schoolkids" .)