He analysed a new challenge here, one of describing a vertical landscape with seven rows of horizontals to achieve distance:
1. Large red geometric rocks;
2. Yellow plain;
3. Front range of hills;
4. Mid-range of hills with geometric interest;
5. Rear strip of plain;
6. Distant hills;
Each area of the horizontals relates to the overall system. The subtle tonal changes in the pale blue of the sky, distant hills and on the tree trunk help tie the composition together.
Ewald suffered a gunshot wound to his head in (October?) 1949, when (aged 19 years) he was playing with a gun, while out at his father’s painting camp at Areyonga. He survived but lost his right eye in the operation attempting to remove the bullet from his brain in Alice Springs Hospital. Rex Battarbee stated that he suffered greatly from the after-effects of the accident, but rose above the disability to paint many works, which may be considered his masterpieces (1971).
Despite the trauma, Ewald appears to have adjusted well in painting with his left eye only after this sudden loss. A survey of scholarly medical literature demonstrates most people who lose an eye fairly early in life, rather than in old age, adjust well and most of them within one year. Ewald would have had approximately a 20 – 25% decrease in the size of his field of view (peripheral vision) and probably an enhanced contrast sensitivity in the remaining eye compared with people with both eyes. Minimal adjustment would have been needed to accommodate distance and perspective. For painting, he would have adjusted for peripheral vision loss by aligning his body slightly and turning his head away from the side of the lost eye so that the good eye centred on the scene being painted. 
While adjusting to his loss of peripheral vision, Ewald created Hermannsburg Watercolour, est 1949-50. (watercolour on paper; 37.4 x 26.4 cm; NGA 13362 2000.474).
This vertical scene of a rocky hill, a tall gum tree and a sky with clouds has no depth of perspective. This was possibly created in the year after the accident, while Ewald was adjusting to his acquired monocular vision. No depth was attempted in this painting by way of distant hills and the vertical composition did not require peripheral vision.
It is a relatively tonal painting and has two areas of pale under wash, one for the sky and the other for the hill. The scene is described rhythmically with small curved marks relating to small straight geometrics. The mood of this painting is one of equilibrium, perhaps on the downbeat side. The resolution of this must have been reassuring to Ewald.
In the same year as the accident, Ewald painted Flame-like Mountains: James Range in a location close to the scene of the accident. This dramatic painting seems to show something of the process of visual recovery, if not yet emotional recovery from the trauma. There is no depth in the painting and it is a vertical composition, not requiring peripheral vision. (Heritage… Fig 4.15 in Gayle Griffiths and Robin Battarbee Collection at Araluen Museum at Alice Springs).
As described later, in the years following the loss of his right eye, Ewald’s landscapes slanted emphatically down to the right, in what the author thinks may have been partly a visual adaption to the loss, but the slanting horizons may also have been an aesthetic choice. The slanting suggests movement in the landscape and most of his landscapes appear animate. In some he combined horizontals in one part and slanting elsewhere in the same painting.
The rocky hills in Central Australia are rich in nature based geometric patterns. After the accident injury Ewald returned to his interest in geometrics and took nature based geometrics further in a stylised form, relieved with curves.