Makes sense to me! I have amblyopia (lazy eye) that wasn't diagnosed til I was 5. Since my eyes don't coordinate I use my L eye as dominant, and had the worst time trying to get an accurate 1/4" seam. Finally realized I tilt my head to the R and wasn't sitting square to the presser foot so I had been making slightly wider than accurate seams. Just off by a few threads, but it adds up! Sort of like looking at the liquid level in a glass measuring cup from the wrong angle ("parallax error"). There's a new line of fabric that is 3D with special glasses- but doesn't work for me.