The most common and most likely answer to this crossword clue is the 3 plus 5 letter word EYE LEVEL
I've seen this crossword clue in The Guardian
E
Y
E
L
E
V
E
L
More clues leading to the result EYE LEVEL
Buddy explains!
The straight part
We know that "where pupils are situated" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case where pupils are situated = eye level.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.