My take from reading the article is that they were able to make a cerebral organoid develop these eye cups. Until now they were either able to make a brain or the eye.
> In previous studies, only pure retinal cells or optic cups were grown in the lab individually. Jay Gopalakrishnan, an organoid expert at University Hospital Düsseldorf, and his colleagues used iPSC-grown mini brains to see if eye structures could develop as an integrated part of the organoid—instead of growing the two parts separately, Science Alert reports.
> In previous studies, only pure retinal cells or optic cups were grown in the lab individually. Jay Gopalakrishnan, an organoid expert at University Hospital Düsseldorf, and his colleagues used iPSC-grown mini brains to see if eye structures could develop as an integrated part of the organoid—instead of growing the two parts separately, Science Alert reports.