Béla Pécz interview on the homepage of the Hungarian Academy of Sciences

In an interview published on the website of the Hungarian Academy of Sciences, Béla Pécz, director of the Technical Physics and Materials Science Research Institute (and previous president of HSM) gives a very elegant and simple description of the reason for the spherical aberration and explains the significance of its correction.
The article is also definitely worth a look at because of the micrographs and figures provided by Béla Pécz and Zsolt Fogarassy.