As the title says, I still did not test, but spear throw is for what I get from the wiki a "quick invoker's attack".
The doubt is if it is considered "ranged" and matching with smart lens description (which would make sense to literal description), or you "throw a melee weapon / attack)" therefore not qualifying as "ranged attack".
I still couldn't finish my current run and I am already planning the next one.. this game is a sickness
Thanks
Ps: well, reading the description of the Google instead of lense, it says "special attacks with ranged weapons". Spear is not a ranged weapons so I guess it wouldn't work.
What a pity, would've been cool, since I will use lenses anyway for night detection throwing spears.. confirmation is appreciated anyway.