Iris was born in Holland and studied the violin with her father, Jo Juda (concertmaster at the Concertgebouw Orkest Amsterdam), Herman Krebbers, and Sandor Vegh in Salzburg. Iris and her father performed as a violin duo for many years.
As a violinist and viola player, Iris has been performing regularly with different European orchestras and ensembles such as the Royal Concertgebouw Orchestra in Amsterdam (violin), the Mozarteum Orchester in Salzburg (principal 2nd violin) and the Hagen Quartet (viola). Iris lived in London for 9 years and during that time, she was a member of the Hanson string quartet, the Nash ensemble (violin), the Johannes ensemble (viola) and the Endymion ensemble (viola). Iris is a founding member of the Chamber Orchestra of Europe and from time to time plays principal viola, both in COE and the Mozarteum Orchestra Salzburg.
Alongside her work with the COE since 1981 (violin), Iris has also been a member of the Lucerne Festival Orchestra since its beginning in 2003 (violin) and the Gaudier ensemble (viola), performing with other members of the COE. She holds the position of principal viola in the Camerata Salzburg. She also plays Austrian folk music alongside her husband Lukas (3 violins and a double bass).
Iris was a member of the EUYO (ECYO) for 4 years from 1979-1982.