eyes

[filanto]

what animal has the biggest eyes?

[bernardo]

Giant squid

[Clanad]

bernardo is essentially correct... as usual.  However no giant squid with eyes as large as the estimate of over 10 inches has been found.  The size is interpolated from smaller examples. The largest eyes for body size is the Tarsier.  The Tarsier is one of the smallest primates and lives in the forests of Borneo, Sumatra and the Philippines. Tarsiers, also known as bush babies, have a maximum body length of 6-1/3 inches and a 10-1/2 inch tail. Their eyes are so large that they would be equivalent to grapefruit-sized eyes in a human being.  Additionally, the ostrich has the actual largest eyes, about 2 inches in diameter, with the horse being next...

[KEJ2000]

No one has mentioned the blue whale.  They must rank high, maybe second?

[bernardo]

The theory about the giant squid is that it has never been captured (or even seen at any reasonably close distance) because it is so good at hearing and/or seeing.  At the depths at which it lives, it is too dark to see any great distance, and the squid can hear/see the noises made by deep-sea diving thingies a mile off.  So it gets scared away long before any humans come near.  Hence the theory that it may have huge eyes.