What a weird thing to discuss. :)

(...)

It is counterintuitive, but the result's a done deal. There are endless
papers on cat contrast sensitivity, all showing the same thing,
basically that a cat's acuity is c.20/100 or so (e.g.,
http://www.animaleyecare.com/for.htm#Vision%20In%20Dogs,%20Horses,%20and%20Cats).
Plus, in bright daylight, the cat's eye isn't working at its best. For
example, the Tapetum Lucidum, the relective layer at the back of the
eye, will tend to reduce acuity is well-lit situations.

So, how can a cat see a fly up on the wall?

Well, cats are much more sensitive than us to low spatial frequencies -
such as low-contrast things near to them. A grey mouse against a grey
wall, for example. Or, if it's close enough, a grey fly on a grey wall.
As Campbell et al (1973; J Physiol 229: 719-731) said, '..cat vision,
just like our vision, is quite sharp and clear but [that] it is
different from ours in that it is attuned to seeing objects well at a
much closer range.' Indoors, the fly up the wall probably isn't very
far from the cat, and so might well fall into the range of sizes that
are well detected, even if the cat cannot make out the hairs on the
fly's kneecaps.

Also, it *can* be a motion thing - motion and form perception are
basically different systems in the brain, and it is possible to be able
to see something moving, but to not be able to see any detail in it
(e.g.,
http://www.vin.com/VINDBPub/SearchPB/Proceedings/PR05000/PR00515.htm).
In cats, IIRC, peripheral vision is more sensitive to motion than in
humans, one main reason being that information from very large areas of
the peripheral visual field is pooled in cats. However, humans are much
better than cats at detecting motion in the centre of the visual field.

So, the cat probably 'sees' the fly in the periphery of vision, but if
you asked said cat, he wouldn't be able to tell you whether it was a
fly or a field of flying fish. Might also be that the cat sees the fly
in peripheral vision, and then orients and tracks it to where it lands.
At which point, the cat can see bugger all there (because the fly has
landed and is still), but being a cat, remains staring at where the fly
presumably is. The human then sees the cat apparently staring right at
a tiny fly. Human then thinks 'mazin, the eyesight on that cat',
whereas the cat is probably thinking 'cannot see a bloody thing, except
that damn wall'.

Incidentally, the Lynx is no better than the domestic cat in terms of
acuity. The Falcon has awesome ability to see fine detail at a distance
though (Uhlrich et al., 1981; Behav Brain Res 2: 291-299).

Another other thing - none of this says the cat's vision is 'blurred',
just that it does not see very fine detail at all; it's simply missing.

Steve.

Yeah, I know lima beans are good for me, but somehow they never even make it
into my grocery cart, much less into my mouth!

Cathy

I've actually found there's a lot of great-tasting stuff that is also good for
me.  The trouble is that it requires shopping for fresh foods and then
preparing said foods.  It's tough for me to find the time.  When I do feel I
have the time, I tend to make bunches of batches and freeze them up for later
...

Oh dear god.

I just realized that, yes, I have become my mother.

Well, based on Oscar's reaction to various foods, I can only guess that
Chicken & Lobster Wellness tastes awful, while Turkey & Salmon Wellness (which
I noticed has whitefish before salmon in the ingredients list; odd) is
apparently the best tasting food she's ever eaten.  Possibly even better than
tuna.