Bowie studied art, music, and design, including layout and typesetting. After Burns introduced him to modern jazz, his enthusiasm for players like Charles Mingus and John Coltrane led his mother to give him a Grafton saxophone in 1961. He was soon receiving lessons from baritone saxophonist Ronnie Ross. He received a serious injury at school in 1962 when his friend George Underwood punched him in the left eye during a fight over a girl. After a series of operations during a four-month hospitalisation, his doctors determined that the damage could not be fully repaired and Bowie was left with faulty depth perception and anisocoria (a permanently dilated pupil), which gave a false impression of a change in the iris's colour, erroneously suggesting he had heterochromia iridum (one iris a different colour to the other); the eye later became one of Bowie's most recognisable features. Despite their altercation, Bowie remained on good terms with Underwood, who went on to create the artwork for Bowie's early albums.