Visual acuity, visual field will be also investigated by the same Neuro-ophthalmologist. Visual acuity will be investigated using best correct Snellen visual acuity. A standardized automated perimetry by humphrey Visual 30-2 field testing will be performed in order to define the presence of visual field deficits Dose selection and radiobiology considerations. The dose selection is based on previous experience with Radiosurgery and Stereotactical Radiotherapy (1, 2, 23, 28, 30), but also on the previous studies concerning the dose tolerance of the anterior visual pathways (38).