A Maddox double prism, also known as a Maddox rod, is a specialized ophthalmic device used in vision testing. The purpose of this prism is to create a separation between two viewpoints, helping individuals with eye alignment issues. While not widely known, there are some alternative terms used interchangeably to refer to a Maddox double prism. These include Maddox cross, Maddox wing, octagon prism, and Polden's prism. Although slight variations might exist, the fundamental concept remains the same. By understanding these synonyms, optometrists and ophthalmologists can effectively communicate and collaborate to provide appropriate treatments for patients with eye alignment and vision-related difficulties.