Which animal species has the largest eyes?

The colossal squid and giant squid have the largest eyes of any animal, each measuring a little over 10.5 inches (270 mm) in diameter. One colossal squid specimen had eyes that measured around 11 inches (280 mm).

In comparison, one of the largest eyes of vertebrates (also mammals) is that of the blue whale; each of its eyes measures about 6 inches in diameter, or the size of a grapefruit.