Eymers began work as a researcher in the experimental physics group of Leonard Ornstein at Utrecht University in 1929 and in 1932 became the head of the teaching laboratory. Ornstein's group did both pure and applied research, with the latter often at the request of businesses or government institutions. Thus it came to be that Eymers published research about atomic emission spectra but her doctoral research concerned the illumination of an art gallery in The Hague. Eymers graduated cum laude with a PhD in 1935 and did postdoctoral research in biophysics, specifically on luminescent bacteria.