  In this paper, we investigate the influence of target anisotropy on two
characteristics of diffusion-controlled reactions: harmonic measure density and
mean first-passage time. First, we compute the volume-averaged harmonic measure
density on prolate and oblate spheroidal targets inside a confining domain in
three dimensions. This allows us to quantify the uniformity of this density in
the small target limit. Second, we derive an explicit expression of the mean
first-passage time to such targets and analyze the effect of anisotropy. In
particular, we illustrate the accuracy of the capacitance approximation for
small targets.
