Hi all.

Has the squid eye developed "better" than the human eye? They don't have a "black spot" as I understand it. Is the design inherently better than with ours?

:welcome: maarek99

I have no informations on squid's visual acuity, but Hughes (1977) reported that the cuttlefish has a very high visual acuity, which is better than that of the cat (!!!) (cited in a paper by Schaeffel et al., 1999)...
Like many other aquatic and non-aquativ invertebrates, cephalopods are also sensitive to the polarization of light 'cos the microvilli within their retina have a special horizontal/vertical arrangement (e. g. see Shashar et al., 1996; Shashar et al., 2000 etc.).... My eyes are not very sensitive to polarized light :wink:, so regarding polarization of light the ceph-eyes are better than my human eyes...

Sorry, that's not quite an answer to your "black spot"-squid-question...

Regards,
TK

I don't know about all cephs, but some of them have the veins feeding the eye from behind, rather than inside. The human eye has a hole where the veins feed through the back then spread out across the retina. This creates the blind spot. Cephs don't have that.

That said, all eyes are "functional" to their specific purpose. The human eye is very generalized, able to see in a wide range of conditions. Other eyes in other creatures are equally specialized to their environment. None is "better". Just specialized to their purpose.

...human eye has a hole where the veins feed through the back then spread out across the retina. This creates the blind spot...

The blind spot in the human eye is not caused by veins passing through the retina... it's the visual nerve which passes through the retina and causes the black spot...

The cephalopod retina is different and doesn't have such an blind area, that's right....

TK