Simplify the following text for a Grade 9 native English-speaking person.
Original: Its limpid , globular eyesâ '' which appear red or blue , also depending on lightingâ '' are proportionately the largest in the animal kingdom at 2.5 cm ( 1 inch ) in diameter .
Simplified: Its limpid , globular eyes , which appear red or blue , depending on lighting , are proportionately the largest in the animal kingdom at 2.5 cm ( 1 inch ) in diameter .