AN EXPERT at the University of Bradford has solved the riddle of a photograph that left people across the world questioning their senses.

The internet was awash with confusion after a widely shared image of a dress at a wedding earlier this year was said to be blue and black by some, and white and gold by others.

Now Marina Bloj and psychologist Karl Gegenfurtner, of the University of Giessen in Germany, have looked at why people saw the dress so differently.

Prof Bloj, professor of Visual Perception within the Bradford School of Optometry, carried out studies on the image with German colleagues.

She said: “The confusion would have never occurred if it was not for the special colours present in the photograph.

"The bluish and yellow colouring in the image correspond to colours that we experience naturally during the course of the day, they lay on what is known as the daylight locus.

“We can normally discount this effect, but in the case of the dress not enough information is available in the photograph so different people make unconsciously different assumptions and as a result perceive the dress differently."

The team adjusted the colour of a disc to correspond to the colours the participants saw in the photograph. Participants reported seeing a range of shades from light blue to dark blue, rather than only white and blue.

The research results are published today in the journal Current Biology.