The iris is made up of two layers. For almost everyone - even people with blue eyes - the back layer (called the pigment epithelium) has brown pigment in it.The front layer of the iris (called the ...

As tens of thousands of marchers crowded the streets in New Zealand’s capital Wellington on Tuesday, the throng of ...

That’s because Luciani has a condition called aphantasia — an inability to picture objects, people and scenes in his mind. When he was growing up, the term didn’t even exist. But now, Luciani, a ...