Hermann Snellen was a famous ophthalmologist known for introducing the Snellen chart, a visual acuity test that is still widely used today. Other synonyms for him include the Snellen eye chart, the Snellen test, or simply Snellen's chart. However, there are other terms that may be used interchangeably with the name of Snellen, including the Landolt C test, the Tumbling E chart, the Sloan chart, and the Orinda chart. All of these methods are designed to measure visual acuity and assist in the diagnosis of eye conditions. While there may be different charts, ultimately they all serve the same purpose - to determine how well an individual can see.