The invention of the light microscope is generally attributed to Zacharias Janssen in the late 16th century (around 1590). However, there is some debate surrounding the exact inventor and the specific date.

Here's why:

* Multiple claims: While Janssen is often credited, some historians argue that Hans Lippershey or Cornelis Drebbel might have independently developed similar instruments around the same time.

* Lack of definitive evidence: There is no surviving documentation or physical evidence from Janssen's time to definitively prove his claim.

Despite the uncertainty, Zacharias Janssen remains the most widely recognized figure associated with the invention of the light microscope, based on contemporary accounts and later historical analysis.