Staring is power. The ability to command another’s gaze, to transfix their mind and muscles by using nothing more than the resolve of one's unblinking eyes, requires discipline and courage of purpose. To stare is to assert one’s existence in the world – to rivet oneself to the now.

A photo taken by the photojournalist Carlos Vera Mancilla in the Chilean capital Santiago this week captures the force of such a glare. The image, caught during demonstrations marking the 43rd anniversary of the military coup that resulted in the overthrow of President Salvador Allende by Augusto Pinochet on 11 September 1973, shows an unintimidated young protester standing toe-to-toe with a heavily-armed riot policeman as she stares with penetrating defiance through his visor.

Taken outside the General Cemetery of Santiago, where Allende is buried and where a memorial to those ‘disappeared’ during Pinochet's regime has been created, the photo represents more than just a staring contest between the opposing perspectives of dissent and order. Vibrating between the pupils of the policeman and those of the protester is a conviction that vision is never merely a passive act but a transformative force – an elemental energy.

“All great and beautiful work”, the English critic John Ruskin believed, “has come of first gazing without shrinking into the darkness.” Though we often talk of the categorical divide between looking and doing, between passivity and activity, Ruskin understood that gazing is itself a species of action and an indispensable component of creation. So did the Romantic poet Wordsworth, who wrote of “the mighty world/Of eye and ear, both what they half create/And what perceive”. To look upon something is to make it into something else by stamping it invisibly, yet indelibly, with the mark of one’s being.

The mesmeric standoff between protester and policeman captured by this week’s photo, in which the reflex of seeing succeeds in generating a more intense image than any physical clash could, raises intriguing questions about the power of looking in culture more widely. Within the realm of art, museum-goers take for granted that seeing is secondary to the primary act of an artwork’s creation – an assumption challenged by the Belgrade-born performance artist Marina Abramović in her 2010 work The Artist is Present.

For more than 736 hours, Abramović stared silently into the eyes of any visitor willing to sit opposite her in an otherwise empty gallery in the Museum of Modern Art in New York. No longer subordinate to the physical stimulus of a painting or sculpture, a drawing or film, the human gaze, both physical and psychological, was suddenly isolated like a previously undiscovered particle – as if it were the very element to which our ability to exist in the world might be traced.

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