Geir competed in four Paralympics, competing in two different sports medaling in both. His first games in 1988 he competed in the swimming events, winning a silver in the 100m breaststroke behind Australian Greg Hammond in a new world record time, he also swam in the 100m freestyle finishing fourth and the 200m medley finishing fifth. At the 1992 Summer Paralympics Geir broke the games record to win the gold in the 100m breaststroke and finished seventh in his heat of the 100m freestyle, he also competed on the track winning a silver in the 100m, finishing fourth in the 200m and 400m. At the 1996 Summer Paralympics Geir competed in just track and field winning three silvers in the 100m, 200m and 400m. Geir also competed in the 2000 Summer Paralympics competing in the same three events he failed to make the final in the 100m and 200m and could only manage seventh.