We report a 17-year, 9-month-old Japanese boy who presented bilateral optic disc drusen with severe progressive visual dysfunction. Static perimetry showed progressive visual field defects, especially in the right eye. The corrected visual acuity in the right eye was 20/20 at the first examination, but decreased to 20/400 during the follow-up period. It remained 20/20 in the left eye. The appearance of the optic disc changed during the follow-up period. The deterioration of the visual function may have been related to growth of the optic disc drusen and/or a regressive change in the vasculature.This patient is the youngest yet reported to have shown this condition, and his visual field defects showed particularly severe deterioration.