
Maryland: Researchers used human retinas grown in a petri dish to discover how an offshoot of vitamin A produces the specialised cells that allow us to see millions of colours, a talent that dogs, cats, and other mammals lack.

Maryland: Researchers used human retinas grown in a petri dish to discover how an offshoot of vitamin A produces the specialised cells that allow us to see millions of colours, a talent that dogs, cats, and other mammals lack.