[Leica] Chromatic aberration/fringing in spectacles?

[pklein at 2alpha.net (Peter Klein)]

Optometrists or anyone who knows the subject:  I just go a new pair of 
bifocals. The distance prescription seems great.  But the reading lenses do 
something I've never experienced before.  When the  gave me a newspaper to 
check how I felt when reading, the contrast of the letters appeared 
noticeably lower my old glasses. Then I realized that large black letters 
had color fringing. I looked at a square picture which was mostly black, 
and I saw a reddish-amber fringe at the top, and a blue fringe at the 
bottom.  Huh?

The young guy fitting my glasses (a technician, not the optometrist who 
does my eye exam) first met my observation with silence. After I insisted 
several times that I was seeing the color fringes, he said that it might 
just be that I was not used to the new prescription, and the fringing would 
go away in time.  But he also said that because I got a frame that had no 
bottom wire, they had to use polycarbonate lenses rather than the generic 
optical plastic I'd had on my previous glasses, and this has slightly less 
good optical properties. He said that they could upgrade the lenses to a 
better material for about $30.  But he advised me to keep them for a couple 
of weeks first and see how I felt then.

   The lighting at the optometrist's was a mixture of sunlight and 
incandescent light.  At home under tungsten light,  I am seeing the same 
fringing on black bars or squares on white paper. The fringes are always 
horizontal lines, not vertical. The fringing doesn't happen without 
glasses, or with my old glasses. Possible confounding factor: It was very 
hot in Sunday night, and I got very little sleep.

Has anyone else ever seen this color fringing with spectacles? Any advice?

--Peter