This study demonstrates that approximately half of patients treated with SRT can expect to maintain functional vision better than HM at 4 years. The rate of visual decline and final vision outcome are independent of location of the tumour in relation to the optic nerve and macula. While it affirms that SRT achieves high rates of local tumour control and eye retention, preservation of functional VA remains an unpredictable endpoint for individual cases and highlights the therapeutic challenge of this treatment modality.