This case report follows the case of a 27 year old female who presented to her optometrist with a 10-day history of floaters in her left eye. The optometrist noted papilloedema and she was advised to attend the Emergency Department for further assessment and imaging. A CT brain showed no acute intracranial findings, however upon examination a left swollen disc was noted and the right pupil was unreactive to light. She was referred to eye casualty for specialist input. Her visual acuity was 0.16 in her right eye and 0.42 in her left eye. Ishihara plates could be read fully. Pupillary reflexes were normal in the left eye however the patient reported that the right eye has been unreactive since birth.