guardian.co.uk: From Leonardo da Vinci to Le Corbusier, the golden ratio is believed to have guided artists and architects over the centuries.Leonardo is thought to have used the golden ratio, a geometric proportion regarded as the key to creating aesthetically pleasing art, when painting the Mona Lisa.Now a US academic believes he has discovered the reason why it pleases the eye.According to Adrian Bejan, professor of mechanical engineering at Duke University in Durham, North Carolina, the human eye is capable of interpreting an image featuring the golden ratio faster than any other.