Animal Kingdom Eye Durability

August 30, 2022 3:57 PM

This might seem like a bizarre question but...which animal has the toughest eyes? Meaning, the least vulnerable to being injured?
posted by tiny frying pan to Pets & Animals (7 answers total)

Best answer: Maybe a snake? There’s a scale over each unblinking eye.
posted by nouvelle-personne at 5:07 PM on August 30, 2022 [2 favorites]

Best answer: Trilobites had hard calcite eyes, but they're not so alive any more
posted by scruss at 5:37 PM on August 30, 2022 [3 favorites]

Best answer: This is not the same thing as mechanical toughness, but Macropinna is a species with a huge clear dome around their eyes; they are pretty well protected!
posted by tchemgrrl at 7:02 PM on August 30, 2022 [2 favorites]

Response by poster: Still hoping for more answers!
posted by tiny frying pan at 1:32 PM on August 31, 2022

Best answer: Trilobites made me think of horseshoe crabs.

You're going to get into the issue of defining what qualifies as "eyes".
posted by intermod at 6:37 PM on August 31, 2022

Best answer: Depends a little on what you consider to be an eye, but the pineal eye of many reptiles and amphibians is usually pretty well-protected and covered by skin. It is an eye in that it is an organ with the primary function of sensing light and communicating that information to the brain, but it's not an image-forming eye (they don't use it to "see" in any conventional sense of the word). But in terms of vulnerability, I'd say they're generally quite well-protected.
posted by biogeo at 12:19 AM on September 1, 2022

Best answer: Also, arthropods in general (including trilobites and horseshoe crabs, as well as insects and crustaceans) have eyes that are covered by their cuticle, the same tissue that composes most of their exoskeleton. In addition to serving as the skin and exoskeleton, the cuticle over the eyes is also a functional part of the eyes, and in at least some cases acts as the lens. So if you feel like having a skin-covered or internal eye is "cheating" as far as ranking the toughest eye, those are relatively tough eyes that are directly exposed to the outside world. The calcite of the trilobite eye was a component of the cuticle, and that seems like a pretty good candidate for toughest eye to me. According to Wikipedia, there's a species of brittle star that may have calcite-lensed eyes similar what trilobites had, but it sounds like that may be disputed. It wouldn't surprise me if there's some still-extant arthropod out there somewhere with calcite lenses, whether or not it's currently known to science.
posted by biogeo at 12:51 AM on September 1, 2022