Flash photography is the easiest way to detect a life-threatening eye cancer called Retinoblastoma. The tumour can develop in young children from birth and often reflects back as a white pupil. Early detection is the key to saving their sight and their lives.
CHECT (Child Eye Cancer Trust) in the UK have developed these ingenious flash photo posters to show parents that they can detect the signs/early signs of eye cancer in their offspring by simply taking a photo.
It's an incredibly innovative and simple use of media, given how we all carry one in our pockets.