This study included148 chordoma and chondrosarcoma patients and 283 individual eyes with functional vision at baseline who received a minimum 30GyRBE to 0.1cm3 of the anterior optic pathway. With a median follow-up of 4.1 years, 5 eyes in 3 patients developed functional blindness, with 2 patients developing bilateral blindness. The 5-year incidence of vision loss was 2.1%. This study concluded that despite the high radiotherapy dose delivered, the rate of vision loss is low and no events occurred in those who received a maximum dose under 60GyRBE.