  We report a detailed study of UGe$_{2}$ single crystals using infrared
reflectivity and spectroscopic ellipsometry. The optical conductivity suggests
the presence of a low frequency interband transition and a narrow free-carrier
response with strong frequency dependence of the scattering rate and effective
mass. We observe sharp changes in the low frequency mass and scattering rate
below the upper ferromagnetic transition $T_C = 53 K$. The characteristic
changes are exhibited most strongly at an energy scale of around 12 meV (100
cm$^{-1}$). They recover their unrenormalized value above $T_C$ and for $\omega
>$ 40 meV. In contrast no sign of an anomaly is seen at the lower transition
temperature of unknown nature $T_x \sim$ 30 K, observed in transport and
thermodynamic experiments. In the ferromagnetic state we find signatures of a
strong coupling to the longitudinal magnetic excitations that have been
proposed to mediate unconventional superconductivity in this compound.
