Appearance of defocused spot

An earlier post about psychophysical effects brings to mind an old
question I have.

If I view a point source but cannot focus on it (say with my
nearsighted eye, or through a low power lens) what I see is not the
classic radially symmetric defocus spot profile. Instead, the spot
has a lot of detail in it, very similar to a laser spot. Yet this
happens with polychromatic spots as well as monochrome ones. I guess I
could be seeing interference effects, but even with white light?

I find I am not the only one who sees this so it is not some strange
thing in my eye.

Now, some have said I am merely seeing retinal structure. But if that
is the case why do I not see it if I look at a printed spot profile of
a defocused spot? Shouldn't the actual profile of the light on my
retina be the same?

.