Q. I have seen some people who seem very Frum check their Esrogim with a magnifying glass. Is that really necessary or even recommended?
A. Horav Shlomo Miller’s Shlit’a opinion that on the onset it is not necessary at all. However, if there is a doubt and a Shaila, in order to clarify the magnifying glass could be helpful.
Rabbi A.Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a