GRIN lenses

[apochronaut]

Aside from the diameter requirement , is there any particular reason I might be missing that GRIN lenses have not been applied to making low magnification microscope objectives?

[abednego1995]

Perhaps cost?
Another would probably be field curvature that cant be compensated with the lens itself.

Cheers,
John

[apochronaut]

Which could be compensated for. It would seem that possibly the benefits of a system with few elements, might challenge the extreme cost of those low power apochromats that reside in the thousands of dollars? Just wondering , really. I have never heard of them being used outside of some fairly small diameter applications.
Apparently, there are numerous ways of preparing the material and lens grinding need not be part of the cost; just surface polishing.