Which test is NOT primarily used to evaluate eccentric fixation?

• A. Major amblyoscope
• B. Visuoscopy
• C. Haidinger's Brushes
• D. Maxwell's spot

Answer: (A)

Eccentric fixation is identified by locating where a person actually fixates on the retina, not at the fovea. Tests that map this fixation locus under different cues are designed to reveal the preferred retinal location used during fixation. Visuoscopy accomplishes this by observing the retinal reflex while the patient fixates a target, letting you see where on the retina the fixation point lies. Haidinger's Brushes use polarization to reveal an entopic image that shifts with the actual foveal location, helping identify the fixation reference point. Maxwell's spot shows a small macular-centered spot under red light, corresponding to the fovea and enabling localization of the fixation point. The major amblyoscope, while a powerful instrument for assessing and treating binocular vision issues such as suppression and misalignment, is not primarily a tool for mapping eccentric fixation; its main role is to evaluate and train binocular function rather than locate the exact fixation locus on the retina.