What Is Unique About The Eyes Of The Giant Squid?

Giant, indeed, are the eyes of this amazing sea monster. They may grow to fifteen inches in diameter, which is as large as some beach balls. The giant squid's eyes are surprisingly similar to the human eye. Both have eyelids, transparent corneas, outer and inner chambers, retinas, lenses, rod cells yielding black and white images and cone cells for registering colour impressions. The structural resemblance is so striking that Dr. N. J. Berrill, a noted biologist, commented: "I think if you asked any zoologist to select the single most startling feature in the whole animal kingdom, the chances are he would say, not the human eye, which by any account is an organ amazing beyond belief, nor the squid-octopus eye, but the fact that these two eyes, man's and squid's, are alike in almost every detail." The 100,000 receptors per square millimetre in the eye of the squid make it possible to see even fine detail.