The most common and most likely answer to this crossword clue is the 2 plus 3 letter word OP ART
I've seen this crossword clue in The Times
O
P
A
R
T
More clues leading to the result OP ART
- Abstract style of old district
- Round fraction is a source of confusion to observers
- Ring section in modern style
- “Moving” style of Vasarely’s old role
- Love role in moving pictures?
- Don’t catch anyone standing for modern style
- Ring member for visually stimulating work
- Circle, a constituent in illusory paintings?
- Old quarter, newer design
- Painting style adopted by Picasso particularly
Buddy explains!
The straight part
We know that "a source of confusion to observers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a source of confusion to observers = op art.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.