  Spheroidal fluid droplets immersed in another fluid and thermally fluctuating
in the shape are considered. The polarizability of the droplet is evaluated up
to the second order in the fluctuation amplitudes and also the previous
first-order calculations from the literature are corrected. The correlation
functions of the polarizability tensor components are found and used to
describe the polarized and depolarized scattering of light, and the Kerr effect
on microemulsions in the limit of small concentration of the droplets. An
alternative simple derivation of the Kerr constant is also given assuming that
the droplet in a weak electric field becomes a prolate ellipsoid. We consider
both the case when the thickness of the surface layer is neglected and when the
droplet is covered by a layer of nonzero thickness. The result differs
significantly from that used in the literature to describe the Kerr-effect
measurements on droplet microemulsions. Due to the difference the bending
rigidity constant of the layer should be increased about two times in
comparison with the value found in the original experiments.
