What problems did Antoine van Leeuwenhoek encounter?

Antoine van Leeuwenhoek faced several challenges during his work, primarily due to the limitations of his time's scientific tools and methods. He encountered difficulties in obtaining high-quality glass for his microscopes, which he crafted himself, and faced skepticism from contemporaries regarding his discoveries and claims. Additionally, his lack of formal scientific training and the isolation of his findings made it challenging to gain recognition and support from the broader scientific community. Despite these obstacles, his meticulous observations laid the groundwork for microbiology.