[cma]

I’m not sure there would be significant contraction at normal screen FOVs and brightness levels. Instead I think when your eye is out of focus the white smeared onto a black background is a much stronger signal than black smeared on a white background, due to visual perception’s inherent gamma curve exaggerating small brightness differences much more against low brightness levels (black background) than against high brightness levels (white background). So there is a much stronger perception of blurriness (black background with a +0.X lumen splotchy patch is exponentially more noticeable than a white background with a -0.X splotchy patch).