Kezys was ordained as a Jesuit priest in the 1950s; he received a master's degree in philosophy from Loyola University (Chicago) in 1956. He founded the Lithuanian Library Press in Chicago, and directed the Lithuanian Youth Center in Chicago between 1974 and 1977.
One of Kezys' first major exhibitions took place in 1965 at the Art Institute of Chicago. Since then his work has been exhibited at a number of American and European museums and in magazines. His photographs are part of the permanent collections at Los Angeles County Museum of Art, the Carnegie Institute in Pittsburgh, Pennsylvania, and at the Art Institute of Chicago. He has published several books.
In May 2000 he participated in an exhibition held in Washington D.C., sponsored by the International Monetary Fund. Kezys operates a small gallery in Stickney, Illinois, featuring the art created by Lithuanian artists around the world, and continues to publish reviews, catalogs, and books on art, religion, and photography.