He noticed when looking into the flames that his boot, interposed between him and the fire, had the characteristic doubled appearance associated with physiological diplopia, or ‘double vision’.... The experience alerted Walters not just to double vision, but also to the indistinct properties of the peripheral field. He immediately began an intensive study of these visual phenomena, and the effects can be seen clearly in Stout Man with Jug c.1936. Here the focus is on the central area, the man’s face, while doubled images flank his nose, which must have been the artist’s point of fixation. Objects are rendered with increasingly large horizontal brush strokes as the painting approaches the edges in an evocation of the relative indistinctness of the peripheral visual field. Within a short time he had produced a substantial body of work, which was exhibited in London in 1936. (http://www.tate.org.uk/research/publications/tate-papers/23/as-seen-modern-british-painting-and-visual-experience)