How many letters does the top answer for “capable of changing the direction (of a light or sound wave)” have?

The most common answer is deflective (10 letters).

Crossword clue: capable of changing the direction (of a light or sound wave)

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

deflective 10 letters wn-def

capable of changing the direction (of a light or sound wave)

refractive 10 letters wn-def

capable of changing the direction (of a light or sound wave)