A magnifying glass is a tool with a curved glass lens that makes objects look bigger than they really are. When you hold it over small text in a book, the letters suddenly appear large and easy to read. When you use it to examine a bug, you can see details like the tiny hairs on its legs or the patterns on its wings that would be invisible to your naked eye.

The magic happens because of the shape of the lens. The curved glass bends light rays in a way that tricks your eye into seeing a larger image. Scientists use magnifying glasses to study specimens, jewelers use them to inspect gems, and detectives in old mystery stories are always pulling them out to search for clues at crime scenes.

Magnifying glasses were invented in the 1200s and transformed what people could learn about the world around them. Before magnifying lenses, people didn’t know that insects had compound eyes or that plants had intricate structures too small to see. The magnifying glass opened up an entire universe of tiny details that had always been there but had remained hidden.