Born in County Donegal, Egan attended St Columb's College in Derry before studying Art in Belfast and Portsmouth and at the Slade School of Art in London.
He painted restrained abstracts in which ghostly squares appear to float to the edge of a monochromatic canvas.
He represented Ireland at the Paris Biennale in 1980 and the São Paulo Art Biennial in 1985.
In 1993 he won the Premier UNESCO Prize for the Arts in Paris, and he received the Gold Award at Cagnes-sur-Mer in 1997.
Major exhibitions of his work were held at the Whitworth Art Gallery, Manchester and the Irish Museum of Modern Art, Dublin in 1995–96, and at the Stedelijk Museum Amsterdam in 1999.