Hermann Snellen

Hermann Snellen was a Dutch ophthalmologist best known for creating the Snellen chart, a tool used to measure visual acuity. The chart displays rows of letters that decrease in size, helping eye care professionals determine how well someone sees at a specific distance, usually 20 feet. By noting the smallest line a person can read accurately, the Snellen chart provides an easy, standardized way to assess visual sharpness and detect vision problems. It remains a widely used and important tool in eye examinations today.