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The animal kingdom contains all manner of visual organs
June 27, 2011 | 4
Trilobites and other ancient members of the arthropod group of invertebrates had compound eyes. In this type of eye an array of identical imaging units, each of which constitutes a lens, beams light to a handful of light-sensitive elements called photoreceptors....[More]
Compound eyes are very effective for small animals, such as this fly, because they offer a wide-angle view and moderate spatial resolution in a small volume.
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Vertebrate animals, including cats (and humans), have eyes that act like cameras. The eye collects and focuses light, converting it into an electrical signal that the brain translates into images....[More]
The hagfish, which lives on the ocean floor, has rudimentary eyes buried under a patch of translucent skin that seem to function not as visual organs but as modulators of circadian rhythms....[More]
Octopuses and squids independently evolved a camera-style eye that superficially resembles the vertebrate eye, but the retina in these cephalopods lacks defects found in the vertebrate retina.
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4 Comments
Add CommentSo the first 'eye' was a light sensor. Some will try to persuade us this happened by accident and some of us will see an act of design. You can never eliminate the possibility that design was involved, however far back you go!
Reply | Report Abuse | Link to thisLet's just admit it's a thing of beauty and wonder. You wouldn't be reading this if it hadn't happened.
I am a creationist and note the article introduced the subject.
Reply | Report Abuse | Link to thisI have serious eye problems .
I see hope in healing the eye by presuming a creator and a common blueprint behind all eyes.
Simply the true equation is a single one. The different kinds of eyes are just trying to do this single equation. Whatever suits you for eyes will be your type. No evolution but simple adaptation.
It follows that a greater equation of what sight is can lead to its healing.
We 'see' with our brains. The sensation of sight starts with the eye; however, the processing of the network of nerves in the retina and the incredible processing in the brain creates the sensation of sight. Animals evolved sight starting with light sensitive cells. Who knows what a being with a compound eye 'sees'. Certainly not a bunch of tiny images but rather an integrated sensation. Even what we perceive as a uniform field of vision is from a far from uniform array of rods and cones.
Reply | Report Abuse | Link to thisThe article in the magazine is exceptional in demonstrating that the development of eyes used for vision evolved from organs and structures that had nothing to do with vision. As with other lines of evidence, it proves nothing by itself, but it's yet another sign along life's highway that says "Evolution straight ahead".
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