Abstract: The effects for ⁶⁰Co γ-radiation on the transmission of severa1 optical glass types, fused silica, dense flint and lanthanum crown, were presented for application in space optics. Transmission spectra in the range of 400-1 100 nm were recorded after exposure to various doses of radiation up to 200 kGy. The results show that for all samples except fused silica, the visible transmission decreases. Although the dense flint and lanthanum crown glass are optically similar before irradiation, they show different transmittance loss after irradiation, dense flint glass having stronger sensitivity to γ-radiation. When the dose increases to some extent, the transmittances loss stops decreasing and becomes steady. In addition, the bare samples are more resistant than those with anti-reflection coatings. Taking these differences into account can help to improve the radiation tolerance of optical system design for space applications.