Why do chinchillas have big eyes?

ive just bin asked this question for my course work. to write wot i think and then to research it. i could be completely wrong here i jus thought il share wot i wrote so far.

i would think it is sumthin to do with predators and warning. because tigers have the white spots on the bk of ears to warn predators awaytricking predators into thinkin they are eyes. so the chinchillas ears may have a simlar meaning by the predators seeing and may not attack as they may be heard by the chinchilla sneaking towards them. for examplethe ears seem to get bigger at the top so they may be able to hear further away by certain miles how big the ears are. or it could just be how they simply look wha they have gained from the past and environment.