Coherence scanning interferometry enables high precision measurements in manifold research and industry applications. In most modern systems, a digital camera (CCD/CMOS) is used to record the interference signals for each pixel. When measuring steep surfaces or using light sources with a broad wavelength spectrum, only a small area of the sensor captures useable interference signals in one frame, so a large fraction of pixels is unused. To overcome this problem and enable measurements with high dynamic range and high scan speeds, we propose the use of an event based image sensor. In these sensors, each pixel independently registers only changes in the signal, which leads to a continuous asynchronous pixel stream of information not based on fixed frame capturing. In this Letter, we show the signal generation, an implementation in a coherence scanning microscope in combination with the nanopositioning and nanometrology machine NPMM-200, and first measurements as promising results for event based interferometry.