Professor Visser is an international expert in the development of fluorescence methods and their applications to the investigation of proteins and membranes both in vitro and in vivo. He is (part-time) professor at the Department of Structural Biology of the Vrije Universiteit Amsterdam and professor at the Department of Biochemistry of Wageningen University. He is the founder of the MicroSpectroscopy Centre (MSC) at Wageningen University (1996) and was the director of the MSC until 2007. The MSC is an established expertise centre in which advanced optical imaging methods have been developed as a tool to answer research questions in cell biology, biochemistry and biophysics. The MSC facilities are also used in (inter)national post-graduate courses in advanced imaging technology in cell biology. His current research interests encompassed the use of advanced fluorescence methods for the investigation of flavoproteins, of FRET-sensors based on visible fluorescent proteins and of protein (un)folding. He also contributed in cell biophysical research related to chemotaxis and plant cell signalling. The methods he has established in his laboratory have attracted collaborations and joint publications with 29 different international researchers (e.g. in the USA, UK, France, Germany, Japan, Russia) and with 16 Dutch national scientists. He is the author or co-author of over 220 publications in scientific journals with a peer review system. He has served at the Advisory Editorial Boards of the Journal of Fluorescence, European Biophysics Journal and Biophysical Chemistry. Since 2006 he has coordinated a European Union Marie Curie Research Training Network (acronym: from FLIM to FLIN) focusing on development and exchange of expertise in advanced fluorescence imaging technology.