Which of the following is incorrect regarding the Maddox rod test?

The Maddox rod test is a diagnostic tool used in optometry and ophthalmology to assess binocular vision and to identify phorias, which are latent misalignments of the eyes. The correct choice indicates that the assertion regarding the test's capacity is inaccurate.

In fact, the Maddox rod test can measure both vertical and horizontal phorias, allowing for a comprehensive assessment of eye alignment at both distance and near. This means that option B is stating that the test cannot measure both types of phorias, which is not true. The test is versatile and can be adapted to evaluate different types of visual alignment issues.

The other statements about the Maddox rod test also help clarify its functionality. It is designed to be utilized for both distance and near assessments, rather than being limited to one or the other. The test does involve minimal equipment, specifically the Maddox rod and a light source, supporting its application in various clinical settings. Therefore, the assertion that it cannot measure both vertical and horizontal phorias is what makes option B incorrect.