The electrooptic Kerr effect and its wavelength dispersion have been measured in glasses representing several compositional systems. The measured Kerr effect was large for glasses having large refractive indices, including 1) glasses containing high concentrations of the heavy metals Pb, Bi, and Tl; 2) glasses with high Nb, Ta, and Ti content; and 3) tellurite glasses. Comparison of Xeff(w=w+0+0), obtained from the measured electrooptic data, to values computed from literature values of Xeff(w=w+w-w) suggest an opposition of the electronic and nuclear contributions to the DC effect.