He served as head physicist of the Philips Natuurkundig Laboratorium.
[1][2] He obtained a PhD in physics from Utrecht University in 1963 under professor Volger with a thesis on electron spin resonance and optical studies of solids.
[2][3] From 1963 to 1966 he worked in the United States at the MIT National Magnetic Laboratory.
Vrehen then returned to the Netherlands and started working at the Philips Natuurkundig Laboratorium.
[4] Vrehen was elected member of the Royal Netherlands Academy of Arts and Sciences in 1988.