Optometry & Visual Performance 121 Volume 14 | Issue 2 | June 2026 Viewpoint • Assessment of Fixation Kenneth J. Ciuffreda, OD, PhD • SUNY College of Optometry • New York, New York Daniella Rutner, OD, MS, MBA • SUNY College of Optometry • New York, New York The ability to fixate accurately and stably is critical for optimal viewing of the world. However, many of our patients do not fixate well.1 This would include those with nystagmus, macular degeneration, optic atrophy, albinism, stroke, traumatic brain injury, and more.1-3 Thus, it is incumbent upon the optometrist and others (e.g., a vision therapist or neurologist) to assess a patient’s fixational ability appropriately. In this paper, various methods for assessing fixation, both traditional clinical and objective approaches, will be considered. Table 1 presents a wide array of the more traditional clinical approaches to assess fixation.1,4,5 Gross visual observation is perhaps the most common and simplest approach, although it requires excellent observational skills and knowledge of potential abnormalities on the part of the clinician (Figure 1). The doctor has the patient fixate upon a small target, such as a pen tip or Wolff wand, for 10 seconds (or more), monocularly and binocularly, and integrates by visual memory what is observed, such as the number of fixational losses and their estimated magnitudes, differences noted between each eye and binocularly, the presence of large saccadic intrusions or drift, subtle nystagmus, and more.1 Then it is repeated across different diagnostic gaze positions (e.g., downgaze in reading). This is an adequate screening tool for detecting gross abnormalities. It can also be performed using the slit-lamp for higher Kenneth J. Ciuffreda, OD, PhD New York, New York SUNY College of Optometry, Distinguished Teaching Professor Emeritus PhD, UC-Berkeley/Optometry, 1977 OD, Massachusetts College of Optometry, 1973 BA, Seton Hall University, 1969 Fellow Dipl-AAO, ARVO, COVD, & NAP magnification and hence better detectional ability, especially for abnormalities such as subtle, small, intermittent nystagmus.1 The next four approaches listed in Table 1 mainly apply to the assessment of eccentric fixation (EF) in amblyopic eyes. The Haidinger brush technique is very useful, as it is easy for the patient to visualize, readily provides both direction and magnitude, and can be performed in a young child. The others listed are rarely used in the clinic. The last approach, however, namely 30-second, lowlight visuoscopy developed by Selenow and Ciuffreda,4 is extremely useful and very informative. It not only provides the EF location but also allows the clinician to observe directly on the retina the actual fixational pattern and the underlying types of eye movements (e.g., increased amblyopic drift). It was based in part on an earlier experiment by Lawwill in 1966,4 in which he observed that excessive light intensity exacerbated, or even“created”(i.e., iatrogenically induced), any fixational abnormalities. Hence, what Selenow and Ciuffreda developed and tested was a low-light technique. Thus, the light intensity of the visuoscope is reduced until the doctor can “just” detect the projected calibrated grid and central target on the patient’s fundus. Of course, the patient readily perceives it. The patient is then instructed to fixate carefully on the central target. Since EF is a time-average, perceptual-motor phenomenon,4 the foveal/macular region is assessed for 30 seconds (or more) to build up a sufficient mental image of the EF’s direction, magnitude, variability, and overall pattern. The observed details are then fully described and recorded. The fellow eye is likewise tested for comparative purposes. It is repeated during the course of therapy to assess for likely reduction and hopefully Gross visual observation Angle kappa determination Blind spot comparison Maxwell's spot Haidinger's brush Visuoscopy Table 1. Traditional Clinical Approaches to Assess Fixation Figure 1. Test of fixation by visual observation
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