DISCLAIMER: Artwork is optimised for large format billboards. To get an experience closest to that of the consumer, please view it full screen on a laptop or larger. Many Australians delay eye tests because declining vision happens so gradually it often goes unnoticed. Simply telling people to book an eye test had proven ineffective. The Hidden Eye Test transformed posters from static advertising into functional self-diagnosis tools. Designed to respond differently depending on the viewer’s eyesight, each poster delivered a personalised experience through visual perception alone. Those with good eyesight saw the eyewear they needed to keep their eyes healthy, while those with bad eyesight saw what they needed more urgently: an eye test, eye scan or eye care. Created in collaboration with optometrists and AI artists, the design was made possible by combining advanced illusion techniques, eye tests, layering high and low frequency images, as well as a meticulous composition of background, wardrobe, shapes, colour and contrast. By blending visual storytelling, optical illusion theory and AI-assisted craft, the work pushed poster design beyond persuasion into function. The campaign drove a 1,398% increase in eye test bookings, a 126% rise in appointments and 134% growth in eyewear sales, proving that innovative design can create real behaviour change at scale.