Visual Impediment Research Articles

Optimized 3D reconstruction in nearshore underwater environments: A cost-effective pre-processing strategy for Neural Radiance Fields implementation

Nearshore oceans, teeming with diverse benthic ecosystems, continue to be a focal point for marine research. While 2D visual representations have been the mainstay in this area, the intricate, multi-dimensional nature of the seafloor ecosystems underscores the need for 3D modeling to capture their full essence. This study unveils a novel approach tailored for static image processing and 3D modeling through Neural Radiance Fields (NeRF), with a particular emphasis on the refined instantNGP variant. A meticulously crafted pipeline is employed, centered on neutralizing the visual impediments brought about by the interplay of light and seawater in underwater imaging. This refined pre-processing strategy ensures that images are primed for a seamless transition to NeRF-based 3D reconstruction, all the while conserving computational resources. The refined image processing techniques rectify underwater color discrepancies, notably the prevalent blue-green hue resulting from unique lighting conditions. Moreover, the system's ability to identify and excise seawater boundaries guarantees that the 3D models remain singularly focused on the richness of the seafloor ecosystems. Remarkably, achieving this does not demand vast datasets or exorbitant computational prowess, positioning it as an ideal fit for processing images from nearshore regions. As a more resource-friendly and efficient counterpart to existing methodologies, this study furnishes marine ecologists with a powerful instrument for RGB-centric 3D renderings of nearshore terrains. Nonetheless, for broader applicability in diverse marine settings, fusing this approach with neural networks could prove invaluable.

Catastrophe optics theory unveils the localised wave aberration features that generate ghost images

Monocular polyplopia (ghost or multiple images) is a serious visual impediment for some people who report seeing two (diplopia), three (triplopia) or even more images. Polyplopia is expected to appear if the point spread function (PSF) has multiple intensity cores (a dense concentration of a large portion of the radiant flux contained in the PSF) relatively separated from each other, each of which contributes to a distinct image. We present a theory that assigns these multiple PSF cores to specific features of aberrated wavefronts, thereby accounting optically for the perceptual phenomenon of monocular polyplopia. The theory provides two major conclusions. First, the most likely event giving rise to multiple PSF cores is the presence of hyperbolic, or less probably elliptical, umbilic caustics (using the terminology of catastrophe optics). Second, those umbilic caustics formed on the retinal surface are associated with certain points of the wave aberration function, called cusps of Gauss, where the gradient of a curvature function vanishes. However, not all cusps of Gauss generate those umbilic caustics. We also provide necessary conditions for those cusps of Gauss to be fertile. To show the potential of this theoretical framework for understanding the nature and origin of polyplopia, we provide specific examples of ocular wave aberration functions that induce diplopia and triplopia. The polyplopia effects in these examples are illustrated by depicting the multi‐core PSFs and the convolved retinal images for clinical letter charts, both through computer simulations and through experimental recording using an adaptive optics set‐up. The number and location of cores in the PSF is thus a potentially useful metric for the existence and severity of polyplopia in spatial vision. These examples also help explain why physiological pupil constriction might reduce the incidence of ghosting and multiple images of daily objects that affect vision with dilated pupils. This mechanistic explanation suggests a possible role for optical phase‐masking as a clinical treatment for polyplopia and ghosting.

Prevalence of visual impairment among patients attending the University of Port Harcourt Teaching Hospital, Rivers State, Nigeria

Visual impairment, also known as loss of vision is the decreased ability of a subject to see to a degree. It is a global concern that is likely to escalate with prolonged life expectancies with increasing attention in the realm of eye care. In this study, the prevalence of visual impairment among patients attending the University of Port Harcourt Teaching Hospital, Rivers state, Nigeria was investigated. The study accessed a total of 7, 345 case notes of ethically sourced, visually impaired subjects who visited the hospital within five years (2015 - 2019) in the target study area. For each year accessed, records were grouped according to participants’ age and gender, then matched with the type and causes of visual impairment in the study area. At the end of data collection, Results were passed through the graph pad prism (version 8.1), and subjected to statistical measure of central tendencies to obtain the average records and prevalence levels for collected variables, while setting confidence interval at a 95%. Differences in means across groups were also confirmed with the One-way analysis of variance (ANOVA), while setting a p value less than 0.05 as statistically significant. Following analysis, study found a statistically significant increase (p < 0.05) in cases of visual impairment for 2019 as compared other year records, even though there was an inconsistent attenuation for the various years compared, with moderate vision having an apparently higher record than other visual impairments. Severe cases came second with 2018 having the highest cases than others but, with moderate impediments. Also, a significant increase (p < 0.05) was seen in refractive error as compared to other causes of visual impediments. We recommend similar but more molecular approach to visual impairments within study area, and more.

Composite axial eyelid flap in the surgical management of orbitopalpebral neurofibromatosis

Background: Orbitopalpebral neurofibroma is a progressive and debilitating disease with the potential of affecting the orbital, temporal and facial region. Lack of capsule and its infiltrative nature yields to difficulty in complete removal. Aims and Objectives: In this interventional case study, nine patients between the ages of 12–30 years diagnosed with orbitopalpebral neurofibromatosis underwent palpebral remodeling with composite axial eyelid flap for esthetic purpose and alleviation of visual impediment. Material and Methods: The clinical course for every individual was scored using Ptosis, Canthal involvement, and Oculopalpebral Diastasis (PCD) score on regular follow-ups. Results: For majority of the cases, an improvement was noted on the PCD scale. Conclusion: This series demonstrates that a tailored approach to each individual helps in attaining a balance between function and esthetic outcomes.

Collective behaviour of fish in the presence and absence of flow

Spatial patterns in moving fish shoals originate from social interactions and are driven by factors that benefit individuals, such as predator avoidance or reduced energy expenditure. How shoaling is influenced by the presence and absence of a flow field is only partially understood. Adopting a reductionist approach, time spent shoaling, shoal structure and information transfer between pairs (the smallest subsystem of a shoal) of Eurasian minnows, Phoxinus phoxinus, were investigated in a recirculating flume in the absence (control) and presence of flow (low and high). Minnows spent more time shoaling under high-flow conditions. The pairs tended to swim in a tandem and side-by-side configuration under static and high flow, respectively, while under low flow, the neighbour's position was more uniformly distributed around the focal fish. Our approach involved analysis of fish accelerations and velocity correlations and indicated that, with the potential for hydrodynamic masking in flowing water, the relative positions adopted reflect the individual's propensity to increase information transfer with its neighbour by visual means so that an energy-efficient configuration can be maintained. Conversely, when the energetic benefits of a side-by-side configuration are lost in the absence of flow, fish limit the costs of the partial visual impediment (on one side) imposed by the presence of a close neighbour by employing a ‘follow-the-leader’ tactic.

A randomized, prospective, comparative trial of a variable-angle versus fixed-angle endoscope for exploratory thoracoscopy in canine cadavers.

To compare the efficacy of a variable-angle endoscope (VAE) for canine thoracoscopic exploration to a traditional fixed-angle endoscope (FAE). Randomized, prospective, comparative study. Five fresh canine cadavers. Twelve predetermined anatomical locations were labeled after median sternotomy in each cadaveric thorax. Two board-certified veterinary surgeons performed thoracoscopic evaluation of each thorax using a fixed-angle (30°) and a variable-angle (0°-120°) endoscope with and without lungs mechanically ventilated. The order of surgeon, lung ventilation, and endoscope were determined using a randomized block design. Time to visualize each anatomical location was compared for surgeon, endoscope, and lung ventilation status. Primary outcome measures were time to individual anatomical location, total simulated thoracoscopic exploration time, and ability to identify anatomical location within the designated time period. Lung ventilation (difference = 184 seconds, P = .015, 95% CI = 45-342 seconds) and endoscope type (difference = 112 seconds, P = .029; 95% CI = 10-213 seconds) had an effect on the cumulative time for complete thoracoscopic exploration. The VAE shortened the time to identify three of the 12 anatomical locations when controlling for the effects of lung ventilation. Use of the VAE did not improve time to identification for any locations compared to the FAE when lungs were not ventilated. The VAE facilitated significantly shorter cumulative thoracoscopic exploration time compared with the FAE. Failure to identify predetermined locations was more common with the FAE than with the VAE. Use of a rigid VAE decreased cumulative thoracoscopic exploration time and provided an alternative to one-lung ventilation for circumventing the visual impediments of lung ventilation. This cadaveric study provides evidence that one-lung ventilation and use of a VAE may improve surgeon efficiency during exploratory thoracoscopy.

Dead but not gone: Female body, surveillance and serial-killing in Alfred Hitchcock's Frenzy

Abstract Alfred Hitchcock in makes the corpse of an ordinary woman both an object of surveillance and a source of active watching. Mrs Bates and Marion in Psycho, Brenda and Babs in may be seen as predecessors to the series of dead women figuratively staring back in films such as The Silence of the Lambs () and Perfume: The Story of a Murderer (). The corpses do not merely offer themselves up as ciphers to be decoded. They reveal the lack in the perpetrators. Hitchcock's Frenzy relies on female bodies for clues to the murders. Hitchcock plays the vital role of bringing about a transition in the way in which women's bodies are to be treated in films, a transition from bodies shrouded by mist and darkness of the noirs to the exhibitionism of naked corpses in brightly lit settings. This article shows that abandonment of the usual tropes of visual impediments such as darkness and fog in Hitchcock's later films suggests a continually developing process of urban surveillance that aids in dehumanizing the victims. Further the post-murder masculinist investigative gaze forces a kind of mock-life on the victims through the relentless search of a killer's live signs on their dead flesh.

The effects of visual impediment on the approaching behavior of harbor porpoise, <i>Phocoena phocoena</i>

Studies on odontocetes (e.g., porpoises) have revealed that these animals may adaptively use vision. The present study examined the contributions of vision to the approaching behavior of the harbor porpoise (Phocoena phocoena). When a porpoise approached a target, the time-to-contact perceived by the animal and its trajectory with a visual impediment condition were compared with those in the control (no impediment) condition. The results suggested that approaching behavior to a stationary target was guided by the animal's evaluation of time-to-contact (τ), maintaining the time derivative of τ () at a constant value. A porpoise with visual deprivation exhibited grater τ value and a longer evaluation time before contact than a porpoise that was not blindfolded in the task of reaching for the target. Furthermore, the porpoise with a visual impediment changed its swimming trajectory toward a target less than the control, which appeared to adaptively adjust its approaching trajectory. These findings imply that the use of vision aided echolocation and enables precise control and alteration of the trajectory during the approach. The present study has implications for adaptive use of vision during approaching behavior in the harbor porpoise.

The Effects of Visual Impediment on the Approaching Behavior of Harbor Porpoise, Phocoena phocoena

Studies on odontocetes (e.g., porpoises) have revealed that these animals may adaptively use vision. The present study examined the contributions of vision to the approaching behavior of the harbor porpoise (Phocoena phocoena). When a porpoise approached a target, the time-to-contact perceived by the animal and its trajectory with a visual impediment condition were compared with those in the control (no impediment) condition. The results suggested that approaching behavior to a stationary target was guided by the animal's evaluation of time-to-contact (τ), maintaining the time derivative of τ () at a constant value. A porpoise with visual deprivation exhibited grater τ value and a longer evaluation time before contact than a porpoise that was not blindfolded in the task of reaching for the target. Furthermore, the porpoise with a visual impediment changed its swimming trajectory toward a target less than the control, which appeared to adaptively adjust its approaching trajectory. These findings imply that the use of vision aided echolocation and enables precise control and alteration of the trajectory during the approach. The present study has implications for adaptive use of vision during approaching behavior in the harbor porpoise.

Augmented Reality (AR) in fingerprint systems for the inclusion in society of people with limited abilities (auditory and language)

At present the various forms of communication are essentia l in addition to being a paramount parameter for the human being, since it allows and facilitates relating, expressing and, above all; transmit or exchange information. All of the living beings communicate in diverse ways, with the use of symbols, audio, images, movements and most importantly through a language composed of words. It is usual to encounter people with some type of physical or menta l limitation. According to data from Instituto Nacional de Estadística y Geografía (INE GI), there is a great number of people with speech and hearing impediments, in Michoacán, for every 1,000 inhabitants there are 69 people with some kind of disability, from which approximately 19.4% of this population can relate directly with speech and communication problems. The majority of the people in any situation lack the ability and knowledge necessary to establish effective communication with people that suffer this type of limitation, like hearing and visual impediment. This is why the presented in vestigation aims to contribute a model proposal, through the Information and Communication Technologies (ICT’s), with the tools of Augmented Reality (AR), that gives and permits the user manipulate accessible and intuitive interfaces, so that the people with hearing and speech disabilities can establish a visual-text communication without the need for intermediaries and with their own sign language.

Partial duplication of the CRYBB1-CRYBA4 locus is associated with autosomal dominant congenital cataract.

Congenital cataract is a rare but severe paediatric visual impediment, often caused by variants in one of several crystallin genes that produce the bulk of structural proteins in the lens. Here we describe a pedigree with autosomal dominant isolated congenital cataract and linkage to the crystallin gene cluster on chromosome 22. No rare single nucleotide variants or short indels were identified by exome sequencing, yet copy number variant analysis revealed a duplication spanning both CRYBB1 and CRYBA4. While the CRYBA4 duplication was complete, the CRYBB1 duplication was not, with the duplicated CRYBB1 product predicted to create a gain of function allele. This association suggests a new genetic mechanism for the development of isolated congenital cataract.

Reflections on marketing and imagination

This commentary on Professor Gerald Zaltman’s essay on Imagination in Marketing first commends the range and depth of this stimulating essay. The author then takes up some specific points made by Dr. Zaltman, illustrating how they have been manifested in his own academic experiences in the world of marketing. Instructional approaches come first, including why the course syllabus was banished from his MBA classroom, and how a special course aimed at stimulating students’ imaginations has evolved over time. Broader issues in the research realm are then addressed, beginning with the posing of a possible relationship between visual impediments and development of imagination. Topics that a new AMA Task Force might wish to address are then discussed, including the dominance of “consequentialism” in Business Schools, the imperialistic tendencies of metrics as applied to scholarly endeavors, the dangers of defining PhD students as immediate producers rather than immediate learners, and the continuing need for a larger view of our sprawling field of Marketing.

Feature article: Lurking in the blind space: Vampyr and the multilinguals

Abstract Carl Th. Dreyer’s Vampyr (1932) has been praised as an avant-garde masterpiece that creates a sense of horror by strategically denying the spectator visual access to key turning points in the plot, including most notably the gruesome vampire attacks. Previous scholarship has treated the visual impediments in the film as deriving primarily from a conscious aesthetic strategy on Dreyer’s part to enhance the sense of mystery and terror by undermining the spectatorial gaze. This article links the visual obfuscation in the film instead to Vampyr’s status as a post-synchronized, multilingual sound film, which motivated Dreyer to deny the spectator a view of the actors’ moving lips. I argue that Dreyer turned a production limitation into an artistic virtue by discursively framing the denial of vision as an overall aesthetic strategy, thus effectively ‘masking’ what could otherwise have been viewed as an embarrassing concession to financial constraints.

2A1-A05 紫外線硬化樹脂点字・触図の新規作成装置の開発(触覚と力覚(1))

Japan has the highest rate of increase with respect to the population of senior citizens. More products, facilities, and services that are accessible to a wider range of people, regardless of their physical qualities or disabilities, are becoming popular. In this study, we focused on visual impediment. Printing braille and tactile maps with clear and colorless ultraviolet curable ink is usually done by screen printing. However, it is pointed out that end result of printed material manufactured by this method is poor quality. Therefore, we developed new printer for braille and tactile map, that clear and colorless ultraviolet curable ink was jetted by nozzle quickly. Furthermore, monitoring evaluation was conducted by several people actually using the Braille manufactured by the new printer. From this monitoring evaluation, we obtained a good appraisal for the braille.

Improved access and visibility during stapling of the ultra-low rectum: a comparative human cadaver study between two curved staplers

BackgroundThe purpose of this study was to compare in human cadavers the applicability of a commonly used stapling device, the CONTOUR® curved cutter (CC) (Ethicon Endo-Surgery, Cincinnati, OH) to a newly released, curved stapler, the Endo GIA™ Radial Reload with Tri-Staple™ Technology (RR) (Covidien, New Haven, CT)MethodsFour experienced surgeons performed deep pelvic dissection with total mesorectal excision (TME) of the rectum in twelve randomized male cadavers. Both stapling devices were applied to the ultra-low rectum in coronal and sagittal configurations. Extensive measurements were recorded of anatomic landmarks for each cadaver pelvis along with various aspects of access, visibility, and ease of placement for each device.ResultsThe RR reached significantly lower into the pelvis in both the coronal and sagittal positions compared to the CC. The median distance from the pelvic floor was 1.0 cm compared to 2.0 cm in the coronal position, and 1.0 cm versus 3.3 cm placed sagitally, p < 0.0001. Surgeons gave a higher visibility rating with less visual impediment in the sagittal plane using the RR Stapler. Impediment of visibility occurred in only 10% (5/48) of RR applications in the coronal position, compared to a rate of 48% (23/48) using the CC, p = 0.0002.ConclusionsThe RR device performed significantly better when compared to the CC stapler in regards to placing the stapler further into the deep pelvis and closer to the pelvic floor, while causing less obstructing of visualization.

Phenotype associated with mutation in the recently identified autosomal dominant retinitis pigmentosa KLHL7 gene.

To characterize the clinical phenotype, with an emphasis on electrophysiologic findings, in a family with autosomal dominant retinitis pigmentosa caused by mutation in the recently identified KLHL7 gene. Eleven patients from a single family were selected from the Swedish retinitis pigmentosa register. Four patients had been examined 13 to 17 years earlier and underwent further ophthalmologic examination, including visual acuity, fundus inspection, Goldmann perimetry, full-field electroretinography (ERG), multifocal ERG, and optical coherence tomography. KLHL7 mutation was identified by sequence analysis. In most examined family members, the fundus showed minor abnormalities. Full-field ERG demonstrated reduced cone and rod function, but rod responses were preserved in some patients late in life. Follow-up (<or=17 years) demonstrated slowly progressive retinal degeneration. In an adolescent family member, cone and rod function was initially normal, but retinitis pigmentosa was confirmed by electrophysiology 17 years later. Optical coherence tomography and multifocal ERG demonstrated macular abnormalities of varying degree among family members. Genetic analysis revealed a heterozygous exon 6 change (c.458C>T) in 7 family members. Observed in 2 Scandinavian families to date, KLHL7 mutation has recently been associated with autosomal dominant retinitis pigmentosa. Clinical examination with long-term follow-up verified a phenotype with a varying degree of retinal photoreceptor dysfunction and, in some family members, with late onset and preserved rod function until late in life. Clinical Relevance Patients with minor retinal abnormalities and normal ERG findings early in life can harbor an autosomal dominant form of retinitis pigmentosa with a varying degree of visual impediment. Some patients with late onset may retain night vision for many years.

Avaliação da Hanseníase: relato de experiência de acadêmicos de enfermagem

O Brasil é o segundo no mundo em novos casos de hanseníase. O controle da doença continua sendo uma meta desafiante. Buscou-se descrever o perfil morfológico de lesões cutâneas e outras seqüelas e analisar a conduta adotada no cuidado de feridas de um grupo de pessoas com seqüelas de hanseníase asiladas em uma instituição não governamental. A experiência de ensino-aprendizagem foi longitudinal, fundamentada na Metodologia Científica da Assistência de Enfermagem, envolvendo pessoas com seqüelas de Hanseníase asilados em uma instituição não governamental do estado de Goiás. O perfil morfológico das lesões foi: déficit visual, madarose, desabamento da pirâmide nasal, reabsorção de dedos e artelhos, amputação de membros, mal perfurante plantar e garra ulnar. Detectou-se prejuízo da cicatrização devido à aplicação direta e rotineira de sabões abrasivos e anti-sépticos nas lesões.

Frequency effects of knowledge of results in learning of a motor task with spatial control demands in visual impairment people

The objective of the present study was to verify the effects of knowledge of results (KR) frequency in learning of a motor skill of adults with visual impairment. Nineteen subjects were distributed into two groups in relation to the diverse conditions of KR frequency used. The 100% frequency group received KR after each trial, while the 50% frequency group received KR in half of the trials. A linear positioning task was used, with spatial control demand. The tested hypothesis is that subjects with visual impediments, who practiced with reduced KR frequency, will demonstrate a higher learning than subjects who practiced with 100% KR, according to the previous results in adults without visual impairments. The data analysis carried out through the ANOVA, exhibit no differences between the groups, showing that reduced frequencies are so effective as high frequencies in the learning of a motor skill in adults with visual impairment.

The effect of a hockey visor and sports goggles on visual function

Background: Despite the potential for eye injury, most hockey players in the National Hockey League do not use a protective face shield. We examined the effect of a hockey visor and sports goggle on visual function to see whether visual impediment is a substantial factor in the resistance to use of protective eyewear.Methods: We measured Snellen visual acuity, Ishihara colour vision and contrast sensitivity and performed Humphrey central 30° and peripheral 30° to 60° threshold perimetry in eight volunteers (10 eyes) with and without a sports goggle and a hockey visor (half face shield). Subjects with normal acuity and normal confrontation fields who did not require presbyopic correction at near were enrolled. Five subjects (10 eyes) had further testing with threshold perimetry of the temporal crescent. The order in which the tests were performed (no mask first, visor first or goggle first) was alternated between subjects.Results: There was no difference in Snellen acuity or Ishihara colour vision, and no statistically significant difference in contrast sensitivity or foveal threshold with or without protective eyewear. The visor caused a statistically significant decrease in the central 30° mean deviation index compared to no mask (p = 0.00 1), but the goggle did not. Each of the peripheral quadrant threshold totals was significantly decreased with the visor compared with no mask (p ≤ 0.05). The 30° to 60° temporal field was better preserved with the goggle than with the visor, but the nasal peripheral field was worse with the goggle than with the visor. Both the visor and the goggle caused a statistically significant decrease of more than 4 decibels in the temporal crescent threshold (p = 0.000).Interpretation: Protective eyewear does not adversely affect Snellen acuity, contrast sensitivity, Ishihara colour vision or foveal threshold. The central 30° field of vision is not affected by the sports goggle and is minimally depressed by the hockey visor. The goggle better preserves the temporal midperipheral field, but, unlike the visor, the goggle caused a monocular nasal lens rim scotoma. Both devices caused a depression of more than 4 dB of the far temporal field beyond 60° (temporal crescent).

Visual Requirements for Reading

We have applied research on the visual psychophysics of reading to low vision assessment. Research on different aspects of the reading process found that reading rate rather than reading comprehension is more sensitive to variations in a subject's visual functioning or the stimulus properties of print. The research identified four different visual factors that significantly affect reading rate: (1) acuity reserve [print size relative to acuity threshold], (2) contrast reserve [print contrast relative to contrast threshold], (3) field of view [number of letters visible], and (4) in cases of maculopathy, central scotoma size. Our research indicates that fluent reading rates can be attained with a restricted field of view, as little as four characters. However, attainment of fluent reading levels requires that print size and contrast should be several times threshold and the diameter of a central scotoma should be less than 22 degrees. Although important clinical studies are lacking, we derived specific visual requirements for different reading rates from published experimental research to provide a starting point and to illustrate how visual requirements could be derived, even with poor correlations. Research has made significant progress toward the development of a comprehensive low vision assessment that will allow the practitioner to identify visual impediments to reading, other than reduced visual acuity. Having more fully characterized a visual impairment, the practitioner may tailor devices or interventions to the individual's needs and capabilities.