For thousands of years, smiling faces have been used as ideograms and as pictograms. Since the 1950s, the smiley face has become part of Earth's popular culture. It is a basic ideogram that portrays a smiling face. One evolution of the ideogram is a three-eyed smiley face that once represented 'hating one's location.' The Smiiile project pays homage to the third eye, also called the mind's eye. It reminds those who see it of the mystical and esoteric concept of a speculative invisible eye that provides perception beyond ordinary sight.