<story><title>Mini brains grown from stem cells developed eye-like features (2021)</title><url>https://www.smithsonianmag.com/smart-news/mini-brains-grown-stem-cells-developed-eyes-can-sense-light-180978478/</url></story><parent_chain><item><author>amelius</author><text>Why a pair of eyes? And not three, four, five, ...?</text></item></parent_chain><comment><author>loa_in_</author><text>Two eyes give a very very significant increase in information provided over one eye, because two eyes is absolute minimum for depth perception. Three eyes and more don&amp;#x27;t provide any significant advantage functionally, except maybe redundancy.</text></comment>
<story><title>Mini brains grown from stem cells developed eye-like features (2021)</title><url>https://www.smithsonianmag.com/smart-news/mini-brains-grown-stem-cells-developed-eyes-can-sense-light-180978478/</url></story><parent_chain><item><author>amelius</author><text>Why a pair of eyes? And not three, four, five, ...?</text></item></parent_chain><comment><author>colechristensen</author><text>Because you’re bilaterian which is a very far back feature and basic aspect of embryonic development. You have two of things mirrored left-right.</text></comment>