Eyen graduated from the University of California Santa Barbara with a bachelor's degree in Communications Studies in 1979. He began his coaching career that same year as an assistant coach at Santa Barbara City College. In 1982, Eyen became head coach at Dos Pueblos High School in Goleta, California, and an assistant coach for UC Santa Barbara in 1984.
NBA coaching career
In 1988, Eyen joined the coaching staff of the Los Angeles Clippers of the NBA. The following year, he became an assistant coach of the Los Angeles Lakers under head coach Mike Dunleavy, staying on Dunleavy's staff through three more teams: the Milwaukee Bucks, Portland Trail Blazers, and the Los Angeles Clippers.