Pick up a dusty old lens from a flea market, an estate sale, or even your own forgotten storage bin, and you might notice something strange glinting beneath the surface of the front element: delicate white threads, odd patterns like spiderwebs or frost creeping across the inside of the glass. That eerie substance is lens fungus — an unwelcome guest in the world of photography that quietly invades optical systems, thrives in darkness and moisture, and, if left untreated, can cause permanent and costly damage to your equipment.
