Euphrasia frigida; The cold eyebright can be found on infertile grasslands, stream banks and open soils. I took the opening picture on thermally heated open ground near Myvatn, hence the expression "cold" makes me wonder... It seems that the systematical ordering of the Euphrasia genus is not quite settled yet . Members of the Euphrasia's are known to parasite on the roots of other plants, especially grasses.
It is a member of the Figwort family (Scrophulariaceae).