Electron radiation presents a peril to the qualification and use of glass on space-based optical systems. Radiation testing of glass for use in harsh radiation environments commonly centers around x-ray, gamma-ray, neutron, and proton radiation. Because of their relatively low energy and density, the effect of electron radiation is often considered negligible. However, during qualification of the TOPEX laser retroreflector array glass, 250 krad (Si) doses of 1.25 MeV electrons were shown to cause significant damage in several glass samples. Electron radiation will generate centers of high potential within the glass and when large enough cause a dielectric breakdown, whereby forming Lichtenberg patterns. These patterns significantly reduce transmission and are good scattering centers. The effect of electron radiation on six types of glass at incremental dosages between 0.25 Mrad and 55 Mrad is presented. The results of electron radiation on a magnesium fluoride anti-reflection coating also are discussed.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.