All Eyes

Eyes are amazing, but even more amazing, if that's possible, is the fact that some creatures can "see" without them. It's a finding that has mesmerized ~ and frustrated ~ the scientists who study it. "We're not just focusing on eyes that look like our eyes," says Duke University biologist Dr. Sönke Johnsen. For example, the new thought about sea urchins, which don't have identifiable eyes and yet seem to be able to see, is that they are, in fact, giant, spiny eyeballs. Octopuses have eyes that we recognize as such, but their skin also contains photoreceptors, and the Asian swallowtail butterfly has a grouping of photoreceptors on its genitals. It comes down to molecules called opsins, which are what allow the photoreceptors in animal retinas to see. “What it means to be an eye is so much broader than we originally thought,” says Johnsen: https://www.sciencenews.org/article/some-animals-%E2%80%98see%E2%80%99-world-through-oddball-eyes?utm_source=Society+for+Science+Newsletters&utm_campaign=e02b1e7c5b-editors_picks_week_of_0516165_21_2016&utm_medium=email&utm_term=0_a4c415a67f-e02b1e7c5b-104586561