It had long been known that people with extraordinary vision like Antico should in theory exist, thanks to an unusual difference in the way their eye is constructed.

Imagine the retina as a kind of mosaic, composed of different kinds of light-sensitive cells known as cones. Most of us have three kinds of cones tuned to different sets of light wavelengths (making us “trichromat”). The light from each part of a scene will activate these cells to different degrees, with the exact combination of signals determining the colour we perceive.

Some women, however, are “tetrachromat”. Thanks to two different mutations on each of the X chromosomes, they have four cones – increasing the combination of colours they should be able to see. The mutation isn’t very rare (estimates of the prevalence vary and depend on your heritage, but it could be as high as 47% among women of European descent), but scientists struggled to find someone who reliably demonstrated enhanced perception.

Then Antico came along, passing a string of tests that showed her vision was different. Studies proved that her tetrachromacy gave her enhanced vision in low lighting – allowing her to see astonishingly vivid scenes at dusk, for instance. After BBC Future broke the story, she soon became famous as the “woman with rainbow vision”.