Certified Ophthalmic Technician Practice Test 2025 – Complete Exam Prep

The Maddox rod is specifically designed to assess phoria, which is a misalignment of the eyes that occurs when binocular vision is not being used. This tool consists of a series of cylindrical lenses or prisms that project light into the eye, creating a comparison of the visual alignment of the eyes. When a patient looks through the Maddox rod, they typically see a line of light or a series of dots that can help reveal any hidden misalignments, allowing for an objective measurement of phoria.

This tool is particularly effective because it isolates the phoria from other potential factors affecting vision, ensuring accurate assessment. In contrast, other options provide different forms of evaluation. For instance, the cover test can diagnose phoria but is not specifically designed for its measurement. An auto-refractor is used to determine refractive error rather than alignment issues, and random dot stereopsis is useful for evaluating depth perception rather than directly measuring phoria.