Oregon’ five-million-acre alien landscape

Through apparently spontaneous change or through mishap or illness, our eyes can change colour in surprising ways.

Our world is awash with a rainbow of colours, but certain shades can have a surprising impact on our ability to concentrate, our mood and even our taste.

From a young age we are primed to choose a favourite colour, but strangely as we grow up our preference often changes – and it's largely due to influences outside our control.