Italian Sign Language or LIS (Lingua dei Segni Italiana) is the visual language employed by deaf people in Italy. Deep analysis of it began in the 1980s, along the lines of William Stokoe's research on American Sign Language in the 1960s. Until recently, most of the studies about Italian Sign Language have dealt with its phonology and vocabulary. According to the European Union for the Deaf, the majority of the 60,000–90,000 Deaf use LIS.