Which type of testing is NOT used to directly determine the angle of anomaly?

• A. Hering Bielchowsky After Image Test (HBAIT)
• B. Haidinger's Brush and Brock Givner After Image test combined
• C. Maxwell's spot
• D. Cuppers Bifoveal Test

Answer: (C)

The ability to determine the angle of anomaly relies on tests that reveal how the two eyes align their images, often by using afterimages or bifoveal fixation to show misalignment. Hering Bielschowsky After Image Test uses the perceived position of afterimages to map the directional misalignment between the eyes. The Haidinger’s Brush and Brock-Givner After Image test likewise harness entopic phenomena and afterimages to reveal vergence differences and how the eyes fuse the image. The Cuppers Bifoveal Test directly evaluates how well each eye can fixate the same target at the same time, giving a direct readout of the deviation angle. Maxwell’s spot, in contrast, is a test of macular pigment and retinal function; it produces a percept due to the eye’s photoreceptor configuration rather than revealing how the eyes align. Therefore, Maxwell’s spot is not used to directly determine the angle of anomaly.