Epilepsy is a disease that affects around 50 million people worldwide, 3–5% of which had seizures triggered by pulsating lights, or by patterns with light and dark areas, a condition known by photosensitive epilepsy (PSE). Video content with fast luminance variations, or with spatial patterns of high contrast — referred to as epileptogenic visual content — may also induce seizures on viewers with PSE, and even cause discomfort on users not affected by this disease. To avoid this type of effects, harmful visual content should be detected before being distributed or displayed. In this paper we propose a method for the automatic detection of flashing video content, compliant with recommendation ITU-R BT. 1702. A key aspect of the proposed method is its computational efficiency, allowing real time implementation at the end-user equipment.