The optical properties in the uv-visible region of epoxy glass composi
te containing 0, 15, 35 and 55% by weight glass microballoons are repo
rted. The obtained optical data are analysed in terms of absorption fo
rmula for non-crystalline materials. Assuming that non-direct transiti
ons in the k-space are involved values of optical band gap (E(opt)) we
re determined. From the Urbach edges, the width of the tail of localiz
ed states in the band gap (E) were evaluated at room temperature.