ooh how about this one: a blown out fovea seems to align with the 'welding' feelings we're getting where the central info blurs out but we can still see.
"The Nyquist frequency, f, is the frequency at which aliasing begins… the foveal Nyquist limit is more like 60 cycles per degree. This may be a result of the hexagonal rather than the rectangular packing of the cone mosaic. The optics of the eye blur the retinal image so that this aliasing is not produced. Using laser interferometry, the optics of the eye can be bypassed so we can reveal this aliasing. We will discuss this in more detail in the chapter on visual acuity."