Born in County Leitrim, Glass studied at Queen's University Belfast; he qualified as a solicitor in 1950 and became a prominent lawyer.
At the October 1974 general election he stood for the Westminster seat of South Belfast, taking second position and almost one quarter of the vote.
Glass was again elected to represent South Belfast on the Northern Ireland Constitutional Convention in 1975.
Glass narrowly failed to be elected to the Northern Ireland Assembly, 1982, and thereafter scaled back his political activities.
He was described by John Wilson QC, Clerk of the Crown for Northern Ireland, as "a gentleman and a scholar.