Light and Space denotes a loosely affiliated art movement related to op art, minimalism and geometric abstraction originating in Southern California in the 1960s and influenced by John McLaughlin. From Wikipedia
The cause of death was heart failure, as confirmed by Arne Glimcher, Founder and Chairman of the international Pace Gallery, which has represented Irwin's work since 1966. With a career that spans over a century, Irwin's work reoriented how viewers perceive space, pushing boundaries within minimalism and abstract expressionism.