As we mammals get older, many?of us start to lose our eyesight because the neurons in our retinas degenerate.? Our retinal ganglion cells might get attacked by glaucoma, or our rods and cones (photoreceptors) might get eroded by macular degeneration or retinitis pigmentosa.? Somewhere in the course of evolution, we lost our ability to regenerate those kinds of cells, just like we lost the ability to regenerate limbs.? Once they’re gone, they’re gone.

But we humans did develop some other things really well:?the ability to use reason and the desire to sustain ourselves.? And those attributes have brought us to the verge of making up for some of our evolutionary shortcomings.?

It’s amazing enough that grow human stem cells into retinal “organoids” —?little balls that all the different types of cells it takes to make a functioning retina, even organized into the right layers.

But now we’ve?learned that if we break up the organoid into individual cells, those cells are?capable of spontaneously forming signal-communicating connections ()?with other retinal cells.? That means that a patient could have their own stem cells grown into retinal cells and applied to their own retina, these new cells could functionally replace the old, and vision could be restored.? No gene therapy required, thanks very much.

You can read all about this last hurdle being at the University of Wisconsin labs of Drs. David Gamm and Xinyu Zhao in the January 4 issue of the Proceedings of the National Academy of Sciences.

For more info with diagrams and pictures: