During a 4‐week balneotherapeutic cure treatment, the optical and acoustical reaction times as well as the flicker and fusion thresholds, using the flicker test, were measured in 2‐day intervals in 44 patients. For comparison 11 healthy inhabitants of this spa were examined in the same way, but without any cure treatment. Confirming earlier results, the course of all measured parameters in the cure patients exhibited a significant circaseptan periodicity, while in the control group no such periodicity was detected.