In Croatia, Glaas families are Slovenes (from Labin ).
Prevalence
Only a few people with faimily name Glaas live in Croatia today, in one household only. They are located in only one small Croatian place, in Rabac (<5).
Outside Croatia
Family name Glaas is present in 12 countries on four continents. "Glaass " is used by few people in the United States.
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.