Is there any point to get more than 10 stacks of Lens-Maker's Glasses?
Solution 1:
No, anything beyond a stack of 10 yields no additional benefits.
From browsing the datamined source code, it looks like critical hits are a true/false toggle -- if you crit, you deal 2x damage, and nothing more/nothing less.
Meaning 10 Lens-Maker's Glasses are the most you need to maintain 100% crit chance. Going above that amount yields no additional benefit, save for having extra backup should you need to convert it into another item should you need them for 3D printers.