"Vision, which consists of an optical system, receptors and image-processing capacity, has existed for at least 520 Myr. Except for the optical system, as in the calcified lenses of trilobite and ostracod arthropods, other parts of the visual system are not usually preserved in the fossil record, because the soft tissue of the eye and the brain decay rapidly after death, such as within 64 days and 11 days, respectively. The Upper Carboniferous Hamilton Formation (300 Myr) in Kansas, USA, yields exceptionally well-preserved animal fossils in an estuarine depositional setting. Here we show that the original colour, shape and putative presence of eumelanin have been preserved in the acanthodii fish Acanthodes bridgei. We also report on the tissues of its eye, which provides the first record of mineralized rods and cones in a fossil and indicates that this 300 Myr-old fish likely possessed colour vision."
It was found in layers of the earth already carefully dated. I understand a large group of people are convinced the earth is young. Wasn't it some dude in the 1800's who took a bible and added up Genesis people lifetimes that came up with the young earth date? Personally, I'm convinced God created the universe including evolution. Evolution is one of God's cool gifts. Pretty sure the pope just said it's not incompatible with Catholic Doctrine. Something along those lines. I'm no expert in religeon. Pretty good at science though, and believe in God and evolution.
Carefully dated? At that claimed age its more like hyper-assumed. What sceintific method has confirmed the beginning conditions were known; the beginning ratio of daughter to parent Isotope were known (zero date problem)l that there was a constant decay rate; that there was no leaching or addition of parent or daughter isotopes; that the forgoing assumptions have been valid for billions of years, etc. Not to mention the extreme difficulty in measuring precisely very small amounts of the various isotopes.
http://www.detectingdesign.com/radiometricdating.html