A sanitary sight indicator for viewing the contents of a production process is provided. The sanitary sight indicator includes a body, an optical unit, and a sanitary connection between the body and the optical unit. The body includes a process-interfacing portion which is adapted to interface with the production process and an optical-interfacing portion which interfaces with the optical unit. The optical unit includes a viewing portion for viewing the contents of the production process and a body-interfacing portion which interfaces with the optical-interfacing portion of the body. The sanitary connection includes a sanitary gasket having a substantially flat annular portion, and first and second annular projections which are approximately semi-circular in cross-sectional shape and which extend outwardly from opposite sides of the annular portion. The sanitary connection further includes a sanitary gasket-groove in each of the optical unit-interfacing portion and the body-interfacing portion. Each of the sanitary-gasket grooves includes a flat surface supporting the flat annular portion of the sanitary gasket and a channel supporting one of the annular projections of the sanitary gasket. Such a sight indicator may be in the form of a "sight flow indicator" for installation in a process line or a "sight window" for installation on a process tank.