Which statement about the Maddox rod test is INCORRECT?

The Maddox rod test is a diagnostic tool used to assess phorias, which are latent deviations in eye alignment. When considering the capabilities of this test, each of the statements reflects its functions.

The test is designed to measure both vertical and horizontal phorias effectively at different distances. It utilizes a rod with a series of vertical or horizontal lines, which, when viewed through one eye, can create a perception that is shifted. This allows for the evaluation of how well the eyes work together and identify any misalignments that may occur.

Specifically, the test can indeed measure vertical phorias at both distance and near, as well as horizontal phorias at these distances. Therefore, it not only assesses vertical phorias but also horizontal phorias, making the statement that claims it cannot measure both types of phorias at both distances incorrect.

This understanding clarifies the capabilities of the Maddox rod test and underscores why the assertion that it cannot measure both vertical and horizontal phorias at distance and near is false.