Late artist Hedda Sterne is a magnificent heroine of art. She died in New York at the age of 100, almost entirely blind, but still drawing “behind my eyes”. In an eight-decade career, Sterne refused to cleave to any single style – no logo, as she drily remarked – unlike the abstract expressionists, with whom she was and remains too closely associated. She ran all the way from self-portraiture to cityscape, still life and collage. Her last exhibition, at 94, was a series of figurative portraits. But it was her appearance in a famous Life magazine photograph in 1951 that restricted Sterne’s reputation. She stands at the back, in a hat, the lone woman among the group of New York School painters, including Jackson Pollock, Robert Motherwell and Willem de Kooning, who had signed a letter of protest against the Metropolitan Museum of Art’s failure to include abstraction in its shows of American art. Late to the shoot, and diminutive in any case, Sterne was asked to clamber up on a table. She stands out among all these men in their surprisingly conservative suits, rising like a feather in a cap. But still she was there in that moment, clinched in what would become exhibit A in any history of abstract expressionism. “I am known more for that darn photo,” she later remarked, “than for 80 years of work.” And so it has seemed, in this country at least; for Sterne has never had a solo exhibition in Britain. This alone would make the show at Victoria Miro momentous. But the gallery has chosen to present a very specific phase of her work – a few years in the early 1960s, inspired by a Fulbright fellowship to Venice, when Sterne began to paint the so-called Vertical-Horizontal pictures. They could hardly have made a better choice. Enter the gallery, and a high, portrait-shaped canvas transmits a startling glow straight at you. It is like walking into a sunset. But that’s not exactly what the painting depicts. Horizontal bars of lavish paint rise in a storeyed format, one above the other. You might call them stripes, to be crude, but they are much more than that. Each is laid on the canvas in relation to the next, in a variety of overlaps, blends, nubs of merging colour of curious moments of ignition, like fireflies or sparks. The significant impression is of an electrifying green, glittering in darkness, like the northern lights. But up close, that exact colour is not there at all. Instead, you see a brilliantly orchestrated arrangement of yellows, black and taupes, setting off an internal light of their own. This apparently simple composition, and its ever-changing effects, approaches the sublime. But is this abstraction, let alone a variant of abstract expressionism? Sterne was adamant in her rejection of both. And none of the works in this show have anything in common with Barnett Newman’s stripes or Mark Rothko’s numinous oblongs. Sterne’s horizontals invoke horizons every time (some of the works are explicitly titled Horizon). And the more these bands multiply, the greater the sense of landscapes and seascapes, of wide skies and watery reflections. The golden crescent near the top of one canvas suggests an actual sunset, but far away in the distance across receding flatlands or tides. Vertical Horizontal #6 from 1963, is a stunning field of opalescent striations, milky blue, silver and cream, with fleeting washes of grey and tan. It slows down the scene, and the weather, and the time of day to a perfect poise, the visual equivalent of a sustained harmonious chord. Late to the shoot and diminutive in any case, Sterne was asked to clamber up on a table. She stands out among all these men in their surprisingly conservative suits, rising like a feather in a cap. But still she was there in that moment, clinched in what would become exhibit A in any history of abstract expressionism Venice was a return to Europe for Hedwig Lindenberg, who was born in Bucharest to Romanian Jews, and married a local businessman, Fritz Stern, in 1932. When the Nazis occupied the city in 1941, he changed his surname to Stafford and helped her escape to New York. The first person she called on arrival was Peggy Guggenheim, who she had met in Paris in the 1930s, and who included her in several group shows. Sterne – she added the “e” – later married the great New Yorker cartoonist Saul Steinberg. Letters between them, in this show, give the fullest sense of their mutual profundity. But he left, after 16 years of infidelity, and she began a life and art of greater freedom. There were huge botanical paintings – the so-called “Lettuces” – installations of crowded faces, canvases painted on the floor, images composed of texts and, in the mid-1990s, white drawings in which she described the flickering interferences of her own macular degeneration. “I walk in the house like a lion every day to keep healthy,” she told an interviewer the year before she died. “I defend myself. I’m ‘invalidated’… But I still learn.” Someone should publish Sterne’s every utterance, one day, as inspiration for the whole human race. Her Venice drawings are exquisite: a wonderfully original grammar of notations. Some are like black silk stitches, varying in length to indicate the shapes of clouds. Others are more like calligraphy, an outlandish handwriting running bottom left to top right, spelling no words, but reading like spiralling clouds. The ink drawings in one room are just radiant little dots, gathering in arcs and horizontals, rather like the paintings. A murmuration of starlings, starry constellations, a ray of light breaking across the Grand Canal: they hold grand visions in their fractional array of marks. And it is this minute observation that underpins the paintings. For there is no way that Sterne could have judged the exact moment at which lead white or slate grey would chime with ochre to get the last glimmer of sunlight without the most intense study of the world before her. She notices the smallest contrast or variation, and incorporates it deep within her paintings. The means appear limited – just swathes on coarse canvas – but the effects are magical, as if light itself were breaking inside these works of art. Hedda Sterne is at Victoria Miro Mayfair, London, until 21 March.