Relative Strength of Central and Peripheral Fusion as a Function of Stimulus Parameters

Cooper, Jeffrey; Feldman, Jerome M.; Eichler, Rachel

doi:10.1097/00006324-199212000-00010

Cited by 8 publications

(2 citation statements)

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“…Even though we tracked only one eye, as the two eyes are yoked binocular vision was normal. Because binocular fusion is mainly driven by peripheral vision (Burian, 1939;Kertesz & Hampton, 1981;Cooper, Feldman, & Eichler, 1992), the location of the simulated scotoma would have been the same in each eye with binocular viewing.…”

Section: Setup and Materialsmentioning

confidence: 99%

Orientation of the preferred retinal locus (PRL) is maintained following changes in simulated scotoma size

2020

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Although macular lesions often enlarge, we know little about what happens when the preferred retinal locus (PRL) is enveloped by the lesion. We present a prospective study of subjects with normal vision who were trained to develop a PRL using simulated scotomas with a gaze-contingent visual display. We hypothesized that, when subjects had developed a robust PRL and the scotoma size was increased, the PRL would move to remain outside the scotoma and in a direction that maintained the orientation (theta) of the PRL relative to the fovea. Nine subjects with normal vision were trained to develop a PRL and were then exposed to scotoma sizes that ranged from 4°to 24°in diameter. Subjects tracked a stimulus using saccades or smooth pursuits. Fixation stability was measured by calculating the bivariate contour ellipse area (BCEA). To measure the reassignment of the oculomotor reference (OMR) to the PRL, we analyzed the spread (BCEA) of saccade first landing points. All subjects developed a robust PRL that did not vary more than 0.8°on average between blocks of trials of a scotoma size, and they maintained the orientation of the PRL as the simulated scotoma size varied (±9°median standard deviation in theta, defined as orientation angle). Fixation stability and OMR to the PRL worsened (larger BCEA) with increasing scotoma size. This, and related studies, could guide development of a PRL training method to help people with central vision loss.

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Section: Setup and Materialsmentioning

confidence: 99%

Orientation of the preferred retinal locus (PRL) is maintained following changes in simulated scotoma size

2020

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“…However, this method usually eliminates monocular depth cues that are ubiquitous in natural environments and drive accommodation and vergence 46 – 52 . Furthermore, the use of non-accommodative targets 48 , 53 – 56 and the absence of peripheral fusional cues 51 , 52 , 57 , 58 in previous studies prevented the accommodation and vergence systems from operating naturally. Finally, the classic method of calculating vergence (Eq.…”

Section: Introductionmentioning

confidence: 99%

A covered eye fails to follow an object moving in depth

Chandna

Badler

Singh

et al. 2021

Sci Rep

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To clearly view approaching objects, the eyes rotate inward (vergence), and the intraocular lenses focus (accommodation). Current ocular control models assume both eyes are driven by unitary vergence and unitary accommodation commands that causally interact. The models typically describe discrete gaze shifts to non-accommodative targets performed under laboratory conditions. We probe these unitary signals using a physical stimulus moving in depth on the midline while recording vergence and accommodation simultaneously from both eyes in normal observers. Using monocular viewing, retinal disparity is removed, leaving only monocular cues for interpreting the object’s motion in depth. The viewing eye always followed the target’s motion. However, the occluded eye did not follow the target, and surprisingly, rotated out of phase with it. In contrast, accommodation in both eyes was synchronized with the target under monocular viewing. The results challenge existing unitary vergence command theories, and causal accommodation-vergence linkage.

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Decompensated exophoria at near, convergence insufficiency and binocular instability: diagnosis and the development of a new treatment regimen

Evans¹

2001

Binocular Vision &Amp; Orthoptics

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Relative Strength of Central and Peripheral Fusion as a Function of Stimulus Parameters

Cited by 8 publications

References 0 publications

Orientation of the preferred retinal locus (PRL) is maintained following changes in simulated scotoma size

Orientation of the preferred retinal locus (PRL) is maintained following changes in simulated scotoma size

A covered eye fails to follow an object moving in depth

Decompensated exophoria at near, convergence insufficiency and binocular instability: diagnosis and the development of a new treatment regimen

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