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

The Maddox rod test is a well-established clinical tool used to assess eye alignment and identify the presence of phorias, including both vertical and horizontal types. The test typically involves the use of a Maddox rod, which creates a line (or a series of lines) that the patient perceives, allowing the clinician to evaluate how the patient's eyes are working together.

The correct answer highlights that the test can indeed measure both vertical and horizontal phorias at both distance and near. This is a fundamental aspect of the Maddox rod test, as it allows for the comprehensive assessment of eye alignment under different conditions.

The other statements about the test also provide valid insights. For instance, the premise that the test is effective for assessing eye alignment reflects its purpose in clinical settings, while the mention of red and white light pertains to how the test is conducted, as the red light from the Maddox rod is contrasted against a white background or light source.

In summary, while the statement that the Maddox rod test cannot be used to measure both vertical and horizontal phorias at varying distances is incorrect, the other statements accurately underscore the test's multifaceted capabilities in evaluating eye alignment and the methods used in its execution.