On the Filling in of the Visual Blind Spot: Some Rules of Thumb

Perception ◽  
1995 ◽  
Vol 24 (7) ◽  
pp. 827-840 ◽  
Author(s):  
Frank H Durgin ◽  
Srimant P Tripathy ◽  
Dennis M Levi
Keyword(s):  
Optic Nerve ◽  
Visual Field ◽  
Apparent Motion ◽  
Surface Segregation ◽  
Blind Spot ◽  
Perceptual Processing ◽  
Occluded Objects ◽  
Rules Of Thumb ◽  
Early Filling ◽  
Blind Spots

In monocular viewing there is a region in the peripheral visual field that is blind owing to the absence of photoreceptors at the site where the optic nerve exits the eye. This region, like certain other blind spots, nonetheless appears filled in. Several novel demonstrations of filling in at the blind spot have recently been reported. Here the implications of many of these effects are critically reevaluated. Specifically, it is argued that many blind-spot phenomena taken to support early filling in (eg pop out and alteration in apparent motion) are actually consistent with the thesis that the visual blind spot is treated by early perceptual processing as a region of reduced or absent information. In support of this, it is shown that many perceptual effects observed in blind-spot completion are similar in detail to the amodally perceived completion of partly occluded objects viewed somewhat peripherally. The goals were to point out striking similarities between blind-spot completion and the amodal completion of occluded parts of surfaces, and to provide a common theoretical framework for understanding these phenomena in the context of surface segregation and perceptual interpolation.

Behavioral evidence of filling-in at the blind spot of the monkey

1994 ◽  
Vol 11 (6) ◽  
pp. 1103-1113 ◽  
Author(s):  
Hidehiko Komatsu ◽  
Ikuya Murakami
Keyword(s):  
Visual Field ◽  
Human Subjects ◽  
Visual Fields ◽  
Blind Spot ◽  
Neural Mechanisms ◽  
Opposite Field ◽  
Normal Visual Field ◽  
Saccade Task ◽  
Behavioral Evidence ◽  
Blind Spots

AbstractIn human subjects, the blind spot is perceptually filled-in by color and brightness from the surrounding visual field. The present behavioral study examined the occurrence of color filling-in at the blind spot in monkeys. First, the location of the blind spot was determined using a monocular saccade task. The blind spots were located on the horizontal meridian at approximately 15–17 deg from the fixation point in the temporal visual field. Then, filling-in at the blind spot was tested by determining if the monkey could discriminate between an annulus presented on the blind spot and a homogeneous disk in the normal visual field. In this task, the monkey was required to make a saccade to a homogeneous disk of the same color and size as an annulus presented simultaneously in the opposite field. Both stimuli were large enough to cover the blind spot and the inner circle of the annulus was confined inside the blind spot. All four monkeys tested performed this task correctly in over 80% of the trials. However, when one eye was covered and the annulus was presented on the blind spot of the uncovered eye, performance deteriorated significantly. To confirm that these results reflected filling-in, one monkey was trained to maintain fixation when two identical homogeneous disks appeared in opposite visual fields. When only one eye was uncovered, and the annulus was presented on the blind spot of the uncovered eye, the monkey maintained fixation in most of the trials. These results show that monkeys were unable to distinguish an annulus from a homogeneous disk when the annulus was presented on the blind spot. This indicates that color filling-in occurs at the blind spot in monkeys and opens possibility to physiological experiments to study the neural mechanisms of filling-in.

Effect of pharyngeal tonsil hypertrophy on the blind spot

1927 ◽  
Vol 23 (2) ◽  
pp. 254-254
Author(s):  
M. I. Volfkovich ◽  
A. Ya. Samoilov
Keyword(s):  
Optic Nerve ◽  
Visual Field ◽  
Blind Spot ◽  
Nerve Function ◽  
Black Plane ◽  
Pharyngeal Tonsil

The authors undertook blind spot examination in adenoidal masses, since the latter allows to detect more subtle changes in optic nerve function. The size of the blind spot was determined by campimetry (sketching the visual field on a black plane 1 meter away from the studied eye). The examination was performed before adenotomy and at various intervals after it.

scholarly journals The coloboma of the choroid simulating optic nerve duplication

2013 ◽  
Vol 6 (2) ◽  
pp. 67-74
Author(s):  
Yuriy Sergeyevich Astakhov ◽  
Yevgeniy Vladimirovich Butin ◽  
Nataliya Vladimirovna Morozova ◽  
Vitaliy Olegovich Sokolov ◽  
Svetlana Sergeevna Florentseva
Keyword(s):  
Optic Nerve ◽  
Visual Field ◽  
Optic Disc ◽  
Radiographic Analysis ◽  
Chorioretinal Atrophy ◽  
Adjoining Area ◽  
Retinal Artery ◽  
Work Up ◽  
Optic Discs ◽  
Blind Spots

In the article, a coloboma of the choroid is described simulating optic disc duplicaton as well as modern possibilities of instrumental work-up methods, which allowed to make a diagnosis. A coloboma (from the Greek koloboma, meaning defect) — is a defect of lid tissues, iris, choroid or optic nerve. A coloboma may be сongenital or acquired. A typical coloboma of the choroid is localized in the lower part of the eye fundus. At times, it comes down to the optic disc, and sometimes involves it as well. The white color of the defect is due to the show-through of the sclera, because the choroid here is completely absent. Corresponding to the coloboma of the choroid, the retina is hypoplastic or absent at times. An optic disc duplication — at this anomaly there are two optic discs on the eye fundus. Sometimes, both may be phtitical and hypoplastic, but more often one of them is hypoplastic, and the second one is performing its function. A true optic disc duplication comes out of the optic nerve partition into 2 or more fascicles. The duplicated optic nerve is pointed out by two optic foramens in one orbit by radiographic analysis, two blind spots in the visual field of one eye, simultaneous central retinal artery pulsation on both optic discs. Ultrasonic B-scanning or OCT and MRI may confirm the existence of a true optic nerve and optic disc duplication. A pseudo-duplication of the optic disc is also very rare and represents a well delineated defect, close to the normal optic disc and simulating an ancillary optic disc with an adjoining area of chorioretinal atrophy.

scholarly journals Blue light blind-spot stimulation upregulates b-wave and pattern ERG activity in myopes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana Amorim-de-Sousa ◽  
Tim Schilling ◽  
Paulo Fernandes ◽  
Yeshwanth Seshadri ◽  
Hamed Bahmani ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Electrical Activity ◽  
Blue Light ◽  
Optic Nerve Head ◽  
Plexiform Layer ◽  
Pattern Electroretinogram ◽  
Blind Spot ◽  
Inner Plexiform Layer ◽  
Pattern Erg ◽  
Myopia Progression

AbstractUpregulation of retinal dopaminergic activity may be a target treatment for myopia progression. This study aimed to explore the viability of inducing changes in retinal electrical activity with short-wavelength light targeting melanopsin-expressing retinal ganglion cells (ipRGCs) passing through the optic nerve head. Fifteen healthy non-myopic or myopic young adults were recruited and underwent stimulation with blue light using a virtual reality headset device. Amplitudes and implicit times from photopic 3.0 b-wave and pattern electroretinogram (PERG) were measured at baseline and 10 and 20 min after stimulation. Relative changes were compared between non-myopes and myopes. The ERG b-wave amplitude was significantly larger 20 min after blind-spot stimulation compared to baseline (p < 0.001) and 10 min (p < 0.001) post-stimulation. PERG amplitude P50-N95 also showed a significant main effect for ‘Time after stimulation’ (p < 0.050). Implicit times showed no differences following blind-spot stimulation. PERG and b-wave changes after blind-spot stimulation were stronger in myopes than non-myopes. It is possible to induce significant changes in retinal electrical activity by stimulating ipRGCs axons at the optic nerve head with blue light. The results suggest that the changes in retinal electrical activity are located at the inner plexiform layer and are likely to involve the dopaminergic system.

Optic Disc Drusen: Longitudinal Aspects, with Emphasis on Visual Field Constriction and Enlarged Blind Spot: A Retrospective Hospital-Based Clinical Series

2016 ◽  
Vol 27 (3) ◽  
pp. 372-378 ◽  
Author(s):  
Hans C. Fledelius
Keyword(s):  
Visual Field ◽  
Optic Disc ◽  
Blind Spot ◽  
Observation Time ◽  
Main Trend ◽  
Visual Field Defects ◽  
Optic Disc Drusen ◽  
Clinical Series ◽  
Field Defects ◽  
Visual Field Constriction

Purpose To examine long-term data on optic disc drusen (ODD) from an outpatient hospital series that indicated more cases with advanced visual field constriction than is apparent from other clinical reports. The underlying pathophysiology is discussed, also with regard to enlarged blind spot, which, in view of the small disc at risk, may seem a paradox. Methods This is an observational retrospective study on an eye clinic series (n = 49), focusing on visual acuity, kinetic/static perimetry, and longitudinal trends, to include the question of eventual visual incapacity. Results Forty-nine patients (32 female and 17 male; bilateral ODD in 45) aged 5-76 years (median age 29 years for both sexes) were included in the study. Observation time was 1-54 years, with serial data recorded over at least 3 years in 25 patients. Visual field defects were found in 32 patients, with ODD considered responsible for the visual field defects demonstrated. Advanced unilateral concentric constriction (for the largest Goldmann object) was recorded in 10 patients, and bilaterally in 2. With regard to nonexplanatory side diagnoses, 2 patients had pituitary adenoma, 1 had a cavernous sinus meningioma, and 1 had neurosurgery for an arachnoid cyst. Conclusions We found more cases of marked visual field constriction than reported in other clinical series. A few such cases appeared acute and vascular, but the main trend was clinically quiet over time. All 49 patients could manage visually in daily life.

scholarly journals A few questions regarding perceptual filling-in of the blind spot

2020 ◽  
Author(s):  
Bernt Skottun
Keyword(s):  
Blind Spot ◽  
Presence And Absence ◽  
The Difference ◽  
Blind Spots

The fact that we are generally unaware of our blind spots is supposed to be the result of the visual systemfilling them in. This brings up the question of what would be the case if no filling-in were to take place.In other words, what would be the difference between the presence and absence of filling-in. The lack of aclear answer to this question makes it unclear what is to be explained by filling-in or even if any explanationis called for. Because filling-in is supposed to be accomplished by some ”mechanism” the lack of an answeralso raises a question regarding what is to be meant by ”mechanisms” in this case.

scholarly journals Visual field map clusters in human cortex

2005 ◽  
Vol 360 (1456) ◽  
pp. 693-707 ◽  
Author(s):  
Brian A Wandell ◽  
Alyssa A Brewer ◽  
Robert F Dougherty
Keyword(s):  
Visual Field ◽  
Functional Mri ◽  
Spatial Organization ◽  
Perceptual Processing ◽  
Large Set ◽  
Human Cortex ◽  
General Properties ◽  
Visual Field Maps

We describe the location and general properties of nine human visual field maps. The cortical location of each map, as well as many examples of the eccentricity and angular representations within these maps, are shown in a series of images that summarize a large set of functional MRI data. The organization and properties of these maps are compared and contrasted with descriptions by other investigators. We hypothesize that the human visual field maps are arranged in several clusters, each comprising a group of maps that share a common foveal representation and semicircular eccentricity map. The spatial organization of these clusters suggests that the perceptual processing within each cluster serves related functions.

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