Well, then I was right. The tablecloth is the same color, no matter
whether I'm wearing my glasses or not. The foliage outside requires
glasses, but single objects of uniform color really shouldn't.
Unless the object is curved, in which case I'll need glasses to see
where the shadows start and stop.
Oh, bother. This vision thing is such a lot of trouble.
The lady at my frame shop sometimes has two pairs of glasses perched
on her nose. I'm simply going to suck it up soon and get bifocals.
--J
On 6/3/07, herownsourgelatine <dlinden_at_jhmi.edu> wrote:
>
>
>
>
>
>
> --- In OliveStarlightOrchestra_at_yahoogroups.com, Bark of Delight
> <barkofdelight_at_...>
> wrote:
> >
> >
> > --- Joy McCann <joy.mccann_at_...> wrote:
> >
> > > So do they really help? Or am I simply being
> > > visually obsessive-compulsive
> > > by putting the glasses on?
> > > ....
> > > Perhaps I'm nuts. Or maybe I need some LSD.
> >
> >
> > Yes to all the above.
> >
> > DJQ to elaborate presently.
> >
> > Bark!
> >
> Here's the deal. If you are looking at a uniform field of a single color,
> it won't matter if
> you have your glasses on or off-- your perception of that color will be the
> same. However,
> if you are looking at a natural scene in which color varies a lot across
> the visual field, then
> having corrected versus blurry vision will have a big impact. Essentially,
> when your vision
> is defocused, then a single cone or small group of cones (the color sensing
> cell type in
> your retina) will be receiving light from multiple adjacent points in your
> visual field. If
> these points have different colors, then those colors will be blended as
> the image blurs.
> You can see this effect another way by taking a slide or video projector
> and twiddling the
> focus knob...
>
> hosg
>
>
Received on 2007-06-03 14:28:04