I could be wrong but tritium on watches usually wasn’t typically used on the face itself, but in gas tubes or vials on the hands and hours markers. Ball, Marath

I could be wrong but tritium on watches usually wasn’t typically used on the face itself, but in gas tubes or vials on the hands and hours markers. Ball, Marathon and Luminox are three popular watch brands that use them currently. Evidently radium stopped being used for lume in 1970, and while tritium faces may have been a replacement around that time, tritium as used only has a lifespan between 12-24 years.