Re: SL3d, focusing of eye

[P3D John W Roberts <roberts@xxxxxxxxxxxxxxxxx>]

>Date: Wed, 16 Oct 1996 11:19:12 -0500
>From: P3D Peter Abrahams  <telscope@xxxxxxxxxx>
>Subject: SL3d, focusing of eye

>I once asked a friend who teaches at a school of optometry, 'what's some
>interesting work in your field lately?'  He told me that some research has
>shown that the eye uses chromatic aberration to cue the ocular muscles for
>increased or decreased accomodation.  I have no citation for this. There is
>other work I have heard of that details how the  eye has difficulty focusing
>in monochromatic light.
>How might this work? (Speculation:) Since blue refracts more than red, the
>blue fringes on the image would move or snap to focus more dramatically than
>the 'main' image.  Or: The near object would be more refracted in the eye &
>have more fringing.

Does the "direction" of the fringing differ based on whether the object is
in front of or behind the current point of focus?

A note of caution: I believe the spatial resolution for human vision is
much less for blue than for the other colors. (I'll try to look it up.)

John R.


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