Julio Le Parc’s art does not ask to be simply observed. It asks to be entered. In his installations light vibrates, surfaces reflect, colours break apart and recombine as visitors move through space. The exhibition at Tate Modern captures this immersive dimension, retracing more than sixty years of work by one of the key figures of kinetic and optical art. Born in Argentina in 1928 and active in Paris from the late 1950s, Le Parc was among the founders of the Groupe de Recherche d’Art Visuel, a collective that in the 1960s challenged the passive role of the spectator and proposed an art grounded in direct experience. The artwork was no longer a static object but a perceptual device, activated by movement and by the presence of the public. The exhibition brings together paintings, sculptures and luminous environments that systematically explore the relationship between form and perception. Modular structures, chromatic sequences and mirrored reflections generate visual instability, questioning the distinction between surface and depth. Movement is often only suggested, yet the eye perceives it as real. In this tension between physical fact and optical illusion lies the core of Le Parc’s research. Alongside its playful and sensory qualities, the work also carries a political dimension. In the 1960s Le Parc rejected the idea of an elitist art and called for direct viewer involvement, in line with a broader critique of institutional structures. Participation thus became not only an aesthetic experience but also a position. The London retrospective allows Le Parc’s work to be reconsidered beyond the historical label of Op Art, recognising its coherence and continuing relevance.