Use of Maddox Rod (in simple ophthalmic terms): The Maddox rod is a subjective test used to assess ocular alignment and detect heterophoria or tropia. Main Uses: Detection of phoria and tropia Helps identify latent squint (phoria) and manifest squint (tropia). Measurement of horizontal deviation Used for esophoria / esotropia and exophoria / exotropia. Measurement of vertical deviation Helps detect hyperphoria or hypophoria. Breaks binocular fusion Converts a point light into a line, preventing