  We report on the optical properties of the hole-doped manganites Nd_{0.7}Sr
_{0.3}MnO_{3}, La_{0.7}Ca_{0.3}MnO_{3}, and La_{0.7}Sr_{0.3}MnO_{3}. The
low-energy optical conductivity in the paramagnetic-insulating state of these
materials is characterized by a broad maximum near 1 eV. This feature shifts to
lower energy and grows in optical oscillator strength as the temperature is
lowered into the ferromagnetic state. It remains identifiable well below Tc and
transforms eventually into a Drude-like response. This optical behavior and the
activated transport in the paramagnetic state of these materials are consistent
with a Jahn-Teller small polaron. The optical spectra and oscillator strength
changes compare well with models that include both double exchange and the
dynamic Jahn-Teller effect in the description of the electronic structure.
