Wonders Wornowiidical

Eyes are meant to be animal inventions. They’re supposed to comprise many cells. They are icons of biological complexity. And yet, here’s a non-animal that packs similar components into its single cell. Is the ocelloid actually an eye? Can it sense light? What does a warnowiid use it for? These questions are still mysteries, but in trying to answer them, Gregory Gavelis...has discovered something about the ocelloid that’s even weirder. At least two of its components—the “retina” and the “cornea”—seem to be made from domesticated bacteria.

Phenomena Ed Yong

The bowl of heaven

It's an unsettling experience, projecting an image of someone's inner eye so neatly into your own, retina examining retina through the intermediary of a lens. It can be disorientating too: gazing down the axis of the beam is like looking up into the night sky with an eyeglass. If the central retinal vein is blocked, the resultant scarlet haemorrhages are described in the textbooks as 'stormy sunset appearance.' I sometimes see pale retinal spots caused by diabetes, and they're reminiscent of cumulus clouds. In patients with high blood pressure the branching, silvered shine on the retinal arteries resembles jagged forks of lightning. The first time I looked into the curved vault of a patient's eyeball I was reminded of those medieval diagrams that showed the heavens as an upturned bowl.

from Adventures in Human Being by Gavin Francis (2015)

Image from Utriusque Cosmi by Robert Fludd (1617)

Self-formation

Self-organisation is so mysterious. We still can’t explain why the cells come together to make an eye. There must be more principles that we still don’t understand yet. It’s something that makes me completely in awe of life.

Yoshiki Sasai, quoted by Mo Costandi in an article titled The man who grew eyes


Image: Human embryonic stem cells organise themselves into embryonic eyes when grown in 3D culture. From Nakano, et al. (2012). Yoshiki Sasai/ RIKEN CDB