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Redondo B, Vera J, Molina R, Molina-Molina A, Jiménez R. Orbicularis oculi muscle activity during computer reading under different degrees of artificially-induced aniseikonia. PeerJ 2024; 12:e17293. [PMID: 38770099 PMCID: PMC11104340 DOI: 10.7717/peerj.17293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 04/02/2024] [Indexed: 05/22/2024] Open
Abstract
Background Aniseikonia is a binocular vision disorder that has been associated with asthenopic symptoms. However, asthenopia has been evaluated with subjective tests that make difficult to determine the level of aniseikonia. This study aims to objectively evaluate the impact of induced aniseikonia at different levels on visual fatigue by measuring the orbicularis oculi muscle activity in the dominant and non-dominant eyes while performing a reading task. Methods Twenty-four collegiate students (24.00 ± 3.86 years) participated in this study. Participants read a passage for 7 minutes under four degrees of aniseikonia (0%, 3%, 5% and 10%) at 50 cm. Orbicularis oculi muscle activity of the dominant and non-dominant eye was recorded by surface electromyography. In addition, visual discomfort was assessed after each task by completing a questionnaire. Results Orbicularis oculi muscle activity increased under induced aniseikonia (i.e., greater values for the 10% condition in comparison to 0%, and 3% conditions (p = 0.034 and p = 0.023, respectively)). No statistically significant differences were observed in orbicularis oculi muscle activity for the time on task and between the dominant and non-dominant eyes. Additionally, higher levels of subjective visual discomfort were observed for lower degrees of induced aniseikonia. Conclusion Induced aniseikonia increases visual fatigue at high aniseikonia degrees as measured by the orbicularis oculi muscle activity, and at low degrees as measured with subjective questionnaires. These findings may be of relevance to better understand the visual symptomatology of aniseikonia.
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Affiliation(s)
- Beatriz Redondo
- Optics, Universidad de Granada, Granada, Granada, Spain
- New England College of Optometry, Boston, MA, United States of America
| | - Jesus Vera
- Optics, Universidad de Granada, Granada, Granada, Spain
- New England College of Optometry, Boston, MA, United States of America
| | - Rubén Molina
- Optics, Universidad de Granada, Granada, Granada, Spain
| | - Alejandro Molina-Molina
- Facultad de Ciencias de la Salud, Universidad San Jorge, Zaragoza, Spain
- Sport and Health University Research Institute (iMUDS), Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain
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2
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Yang B, Intoy J, Rucci M. Eye blinks as a visual processing stage. Proc Natl Acad Sci U S A 2024; 121:e2310291121. [PMID: 38564641 PMCID: PMC11009678 DOI: 10.1073/pnas.2310291121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 02/12/2024] [Indexed: 04/04/2024] Open
Abstract
Humans blink their eyes frequently during normal viewing, more often than it seems necessary for keeping the cornea well lubricated. Since the closure of the eyelid disrupts the image on the retina, eye blinks are commonly assumed to be detrimental to visual processing. However, blinks also provide luminance transients rich in spatial information to neural pathways highly sensitive to temporal changes. Here, we report that the luminance modulations from blinks enhance visual sensitivity. By coupling high-resolution eye tracking in human observers with modeling of blink transients and spectral analysis of visual input signals, we show that blinking increases the power of retinal stimulation and that this effect significantly enhances visibility despite the time lost in exposure to the external scene. We further show that, as predicted from the spectral content of input signals, this enhancement is selective for stimuli at low spatial frequencies and occurs irrespective of whether the luminance transients are actively generated or passively experienced. These findings indicate that, like eye movements, blinking acts as a computational component of a visual processing strategy that uses motor behavior to reformat spatial information into the temporal domain.
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Affiliation(s)
- Bin Yang
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY14627
- Center for Visual Science, University of Rochester, Rochester, NY14627
| | - Janis Intoy
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY14627
- Center for Visual Science, University of Rochester, Rochester, NY14627
| | - Michele Rucci
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY14627
- Center for Visual Science, University of Rochester, Rochester, NY14627
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Wolffsohn JS, Lingham G, Downie LE, Huntjens B, Inomata T, Jivraj S, Kobia-Acquah E, Muntz A, Mohamed-Noriega K, Plainis S, Read M, Sayegh RR, Singh S, Utheim TP, Craig JP. TFOS Lifestyle: Impact of the digital environment on the ocular surface. Ocul Surf 2023; 28:213-252. [PMID: 37062428 DOI: 10.1016/j.jtos.2023.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/18/2023]
Abstract
Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as "the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing". Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not 'diagnostic' of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts).
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Affiliation(s)
- James S Wolffsohn
- College of Health & Life Sciences, School of Optometry, Aston University, Birmingham, UK; Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.
| | - Gareth Lingham
- Centre for Eye Research Ireland, Technological University Dublin, Dublin, Ireland
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Byki Huntjens
- Division of Optometry and Visual Sciences, City, University of London, EC1V 0HB, UK
| | - Takenori Inomata
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Saleel Jivraj
- College of Health & Life Sciences, School of Optometry, Aston University, Birmingham, UK
| | | | - Alex Muntz
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
| | - Karim Mohamed-Noriega
- Department of Ophthalmology, University Hospital and Faculty of Medicine, Autonomous University of Nuevo León (UANL). Monterrey, 64460, Mexico
| | - Sotiris Plainis
- College of Health & Life Sciences, School of Optometry, Aston University, Birmingham, UK; Laboratory of Optics and Vision, School of Medicine, University of Crete, Greece
| | - Michael Read
- Division of Pharmacy and Optometry, The University of Manchester, Manchester, UK
| | - Rony R Sayegh
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Sumeer Singh
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Tor P Utheim
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Jennifer P Craig
- College of Health & Life Sciences, School of Optometry, Aston University, Birmingham, UK; Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
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Vera J, Redondo B, Ortega-Sanchez A, Molina-Molina A, Molina R, Rosenfield M, Jiménez R. Blue-blocking filters do not alleviate signs and symptoms of digital eye strain. Clin Exp Optom 2023; 106:85-90. [PMID: 35057697 DOI: 10.1080/08164622.2021.2018914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
CLINICAL RELEVANCE There is some controversy about the utility of prescribing blue-blocking filters to mitigate digital eye strain. We found that using commercially available blue-blocking filters was ineffective in reducing orbicularis oculi muscle activity and visual symptomatology during a 30-min reading task from a computer screen. BACKGROUND There are some claims that blue-blocking (B-B) filters may be effective in reducing symptoms and signs of digital eye strain. However, recent studies have suggested that there is no sufficient evidence to support their use. This study assessed the short-term effects of a commercially available, B-B filter on orbicularis oculi (OO) muscle activity and symptoms of digital eye strain during the execution of a 30-min reading tas. METHODS Twenty-three healthy young adults (22.9 ± 3.2 years of age) performed two reading tasks from a computer screen with or without a B-B filter on two different days. OO muscle activity was recorded by surface electromyography 4-5, 9-10, 14-15, 19-20, 24-25 and 29-30 min into the trial. Participants reported their perceived levels of visual discomfort and activation before and after completing the reading task. RESULTS A Bayesian analysis favoured the null hypothesis that there was no change in OO muscle activity with or without using the B-B filter (Bayes Factor01 [BF01] = 7.08). Regarding symptomatology, the analysis favoured the time model that reading increased visual fatigue and discomfort but reduced activation levels (BF01 < 0.33 in all cases). However, our data did not support the alternative model that using B-B filter affected these visual symptoms. CONCLUSIONS The B-B filter did not alter OO muscle activity or visual symptomatology significantly during the execution of a 30-min reading task in asymptomatic subjects. These findings support the idea that B-B filters do not attenuate signs and symptoms of digital eye strain.
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Affiliation(s)
- Jesús Vera
- Claro (Clinical and Laboratory Applications of Research in Optometry) Research Group, Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
| | - Beatriz Redondo
- Claro (Clinical and Laboratory Applications of Research in Optometry) Research Group, Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
| | | | - Alejandro Molina-Molina
- Universidad San Jorge, Campus Universitario, Zaragoza, Spain.,Department of Physical Education and Sports, Faculty of Sports Sciences, University of Granada, Granada, Spain
| | - Rubén Molina
- Claro (Clinical and Laboratory Applications of Research in Optometry) Research Group, Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
| | | | - Raimundo Jiménez
- Claro (Clinical and Laboratory Applications of Research in Optometry) Research Group, Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
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Doughty MJ. Assessment of short‐term variability in human spontaneous blink rate during video observation with or without head / chin support. Clin Exp Optom 2021; 99:135-41. [DOI: 10.1111/cxo.12326] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/09/2015] [Accepted: 05/09/2015] [Indexed: 11/28/2022] Open
Affiliation(s)
- Michael J Doughty
- Department of Vision Sciences, Glasgow‐Caledonian University, Glasgow, Scotland, United Kingdom,
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Mork R, Falkenberg HK, Fostervold KI, Thorud HMS. Discomfort glare and psychological stress during computer work: subjective responses and associations between neck pain and trapezius muscle blood flow. Int Arch Occup Environ Health 2019; 93:29-42. [PMID: 31286223 DOI: 10.1007/s00420-019-01457-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 06/30/2019] [Indexed: 11/30/2022]
Abstract
PURPOSE Exposure to additional environmental stress during computer work, such as visual and psychological demands, is associated with increased eye and neck discomfort, altered moods, and reduced well-being. The aim of this study is to elucidate further how subjective responses in healthy, young females with normal binocular vision are affected by glare and psychological stress during computer work, and to investigate possible associations between trapezius muscle blood flow and neck pain development. METHODS 43 females participated in a laboratory experiment with a within-subject design. Four 10-min computer work conditions with exposure to different stressors were performed at an ergonomically optimal workstation, under the following series of conditions: no additional stress, visual stress (induced as direct glare from a large glare source), psychological stress, and combined visual and psychological stress. Before and immediately after each computer work condition, questionnaires regarding different visual and eye symptoms, neck and shoulder symptoms, positive and negative state moods, perceived task difficulty, and perceived ambient lighting were completed. Associations between neck pain and trapezius muscle blood flow were also investigated. RESULTS Exposure to direct glare induced greater development of visual/eye symptoms and discomfort, while psychological stress exposure made participants feel more negative and stressed. The perception of work lighting during glare exposure was closely related to perceived stress, and associations between visual discomfort and eyestrain, and neck pain were observed in all conditions. Furthermore, participants with high trapezius muscle blood flow overall reported more neck pain, independent of exposure. CONCLUSIONS Exposure to visual and psychological stresses during computer work affects the development of symptoms and negative moods in healthy, young females with normal binocular vision, but in different ways. The results also demonstrate the complex interactions involved in symptom development and lighting appraisal during computer work. When optimizing computer workstations, the complexity of the field must be taken into account, and several factors, including visual conditions, must be considered carefully.
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Affiliation(s)
- Randi Mork
- Department of Public Health Science, Norwegian University of Life Sciences, Ås, Norway.,Department of Optometry, Radiography and Lighting Design, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, P.O. Box 235, Kongsberg, 3603, Norway
| | - Helle K Falkenberg
- Department of Optometry, Radiography and Lighting Design, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, P.O. Box 235, Kongsberg, 3603, Norway
| | | | - Hanne-Mari Schiøtz Thorud
- Department of Optometry, Radiography and Lighting Design, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, P.O. Box 235, Kongsberg, 3603, Norway.
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Yuhas PT, Shorter PD, McDaniel CE, Earley MJ, Hartwick AT. Observer-perceived light aversion behaviour in photophobic subjects with traumatic brain injury. Clin Exp Optom 2019; 102:621-626. [PMID: 31037766 DOI: 10.1111/cxo.12896] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 01/29/2019] [Accepted: 02/15/2019] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Photophobia is a common sequela of traumatic brain injury (TBI). Diagnostic tools for this debilitating condition are lacking. This investigation sought to determine whether masked observers can distinguish subjects with TBI-associated photophobia from matched controls based on video recordings of their ocular responses to light stimulation. METHODS Cohorts of students (n = 20), photophobic TBI subjects (n = 28) and their matched control subjects (n = 12) were recruited. A custom pupillometer delivered bright (1013 -1014 photons/s/cm2 ), flashing (0.10 Hz) red (625 nm) and blue (470 nm) light stimuli to subjects, and consensual pupil light responses were recorded. Using a five-point scale, masked observers later graded light aversion behaviour in the pupil video recordings obtained from the student cohort based on observed blinking, tearing and squinting. A grading scale was developed and used by masked observers to grade light aversion behaviour in videos obtained from subjects with post-TBI photophobia and the matched controls. These subjects also scored their perceived discomfort during each light pulse using a five-point scale. RESULTS The subjects in the TBI cohort scored both the blue and red flashing stimuli as evoking more discomfort, relative to control subjects, consistent with their reported photophobia. There was strong agreement among the masked observers for their grades of light aversion behaviour in the videos of ocular light stimulation (interclass correlation co-efficient = 0.78; 29 per cent perfect concordance). However, the median grades for the videos obtained from the TBI subject cohort were not significantly different from those for the control group. CONCLUSIONS Clinicians cannot diagnose TBI-related photophobia based solely on video recordings of ocular responses to light. The need remains for an objective test to diagnose and manage this prevalent post-TBI symptom.
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Affiliation(s)
- Phillip T Yuhas
- College of Optometry, Ohio State University, Columbus, Ohio, USA
| | - Patrick D Shorter
- College of Optometry, Ohio State University, Columbus, Ohio, USA.,Directed Energy Bioeffects Division, Air Force Research Laboratory, San Antonio, Texas, USA
| | | | - Michael J Earley
- College of Optometry, Ohio State University, Columbus, Ohio, USA
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A Randomized Trial to Evaluate the Effect of Toric Versus Spherical Contact Lenses on Vision and Eyestrain. Eye Contact Lens 2018; 45:28-33. [PMID: 30562274 PMCID: PMC6319569 DOI: 10.1097/icl.0000000000000528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To compare the effect of toric versus spherical soft contact lenses on objective measures of visual performance using visual acuity and electromyography of the orbicularis oculi muscle. METHODS Current soft contact lens wearers with -0.75 to -1.75 D astigmatism in each eye were binocularly fitted with toric (1-Day ACUVUE MOIST for astigmatism) and spherical (1-Day ACUVUE MOIST) contact lenses in random order. After each fitting and at 1-week follow-up, high- and low-contrast visual acuities were measured. Electromyography was used to objectively evaluate eyestrain. Linear mixed models were used to assess differences between toric and spherical contact lenses. RESULTS The mean age (±SD) of the 60 participants was 27.5±5.0 years, spherical refractive error was -3.68±2.01 D, and cylinder was -1.28±0.36 D. High- and low-contrast visual acuities with toric lenses were better than with spherical lenses at both fitting (toric high-contrast: -0.065±0.078 and low-contrast: 0.133±0.103 vs. spherical high-contrast: 0.001±0.104 and low-contrast: 0.224±0.107) and follow-up (toric high-contrast: -0.083±0.087 and low-contrast: 0.108±0.107 vs. spherical high-contrast: -0.015±0.095 and low-contrast: 0.211±0.104) (all P<0.0001). Electromyography-measured eyestrain was less with toric versus spherical contact lenses at fitting (least-square ratio of toric over spherical=0.72; P=0.0019) but not at follow-up (ratio=0.86; P=0.11). CONCLUSION These results suggest that toric contact lenses provided improved objective measures of vision in a low-to-moderate astigmatic population.
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Five levels of performance and two subscales identified in the computer-vision symptom scale (CVSS17) by Rasch, factor, and discriminant analysis. PLoS One 2018; 13:e0202173. [PMID: 30153272 PMCID: PMC6112632 DOI: 10.1371/journal.pone.0202173] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 07/30/2018] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To quantify the levels of performance (symptom severity) of the computer-vision symptom scale (CVSS17), confirm its bifactorial structure as detected in an exploratory factor analysis, and validate its factors as subscales. METHODS By partial credit model (PCM), we estimated CVSS17 measures and the standard error for every possible raw score, and used these data to determine the number of different performance levels in the CVSS17. In addition, through discriminant analysis, we checked that the scale's two main factors could classify subjects according to these determined levels of performance. Finally, a separate Rasch analysis was performed for each CVSS17 factor to assess their measurement properties when used as isolated scales. RESULTS We identified 5.8 different levels of performance. Discriminant functions obtained from sample data indicated that the scale's main factors correctly classified 98.4% of the cases. The main factors: Internal symptom factor (ISF) and external symptom factor (ESF) showed good measurement properties and can be considered as subscales. CONCLUSION CVSS17 scores defined five different levels of performance. In addition, two main factors (ESF and ISF) were identified and these confirmed by discriminant analysis. These subscales served to assess either the visual or the ocular symptoms attributable to computer use.
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10
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Mork R, Falkenberg HK, Fostervold KI, Thorud HMS. Visual and psychological stress during computer work in healthy, young females-physiological responses. Int Arch Occup Environ Health 2018; 91:811-830. [PMID: 29850947 PMCID: PMC6132651 DOI: 10.1007/s00420-018-1324-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 05/22/2018] [Indexed: 11/26/2022]
Abstract
Purpose Among computer workers, visual complaints, and neck pain are highly prevalent. This study explores how occupational simulated stressors during computer work, like glare and psychosocial stress, affect physiological responses in young females with normal vision. Methods The study was a within-subject laboratory experiment with a counterbalanced, repeated design. Forty-three females performed four 10-min computer-work sessions with different stress exposures: (1) minimal stress; (2) visual stress (direct glare); (3) psychological stress; and (4) combined visual and psychological stress. Muscle activity and muscle blood flow in trapezius, muscle blood flow in orbicularis oculi, heart rate, blood pressure, blink rate and postural angles were continuously recorded. Immediately after each computer-work session, fixation disparity was measured and a questionnaire regarding perceived workstation lighting and stress was completed. Results Exposure to direct glare resulted in increased trapezius muscle blood flow, increased blink rate, and forward bending of the head. Psychological stress induced a transient increase in trapezius muscle activity and a more forward-bent posture. Bending forward towards the computer screen was correlated with higher productivity (reading speed), indicating a concentration or stress response. Forward bent posture was also associated with changes in fixation disparity. Furthermore, during computer work per se, trapezius muscle activity and blood flow, orbicularis oculi muscle blood flow, and heart rate were increased compared to rest. Conclusions Exposure to glare and psychological stress during computer work were shown to influence the trapezius muscle, posture, and blink rate in young, healthy females with normal binocular vision, but in different ways. Accordingly, both visual and psychological factors must be taken into account when optimizing computer workstations to reduce physiological responses that may cause excessive eyestrain and musculoskeletal load.
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Affiliation(s)
- Randi Mork
- Department of Public Health Science, Norwegian University of Life Sciences, Ås, Norway.
- Department of Optometry, Radiography and Lighting Design, University of South-Eastern Norway, National Centre for Optics, Vision and Eye Care, P.O. Box 235, 3603, Kongsberg, Norway.
| | - Helle K Falkenberg
- Department of Optometry, Radiography and Lighting Design, University of South-Eastern Norway, National Centre for Optics, Vision and Eye Care, P.O. Box 235, 3603, Kongsberg, Norway
| | | | - Hanne Mari S Thorud
- Department of Optometry, Radiography and Lighting Design, University of South-Eastern Norway, National Centre for Optics, Vision and Eye Care, P.O. Box 235, 3603, Kongsberg, Norway
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Sheppard AL, Wolffsohn JS. Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol 2018; 3:e000146. [PMID: 29963645 PMCID: PMC6020759 DOI: 10.1136/bmjophth-2018-000146] [Citation(s) in RCA: 221] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/16/2018] [Accepted: 03/27/2018] [Indexed: 12/31/2022] Open
Abstract
Digital device usage has increased substantially in recent years across all age groups, so that extensive daily use for both social and professional purposes is now normal. Digital eye strain (DES), also known as computer vision syndrome, encompasses a range of ocular and visual symptoms, and estimates suggest its prevalence may be 50% or more among computer users. Symptoms fall into two main categories: those linked to accommodative or binocular vision stress, and external symptoms linked to dry eye. Although symptoms are typically transient, they may be frequent and persistent, and have an economic impact when vocational computer users are affected. DES may be identified and measured using one of several available questionnaires, or objective evaluations of parameters such as critical flicker–fusion frequency, blink rate and completeness, accommodative function and pupil characteristics may be used to provide indices of visual fatigue. Correlations between objective and subjective measures are not always apparent. A range of management approaches exist for DES including correction of refractive error and/or presbyopia, management of dry eye, incorporating regular screen breaks and consideration of vergence and accommodative problems. Recently, several authors have explored the putative role of blue light-filtering spectacle lenses on treating DES, with mixed results. Given the high prevalence of DES and near-universal use of digital devices, it is essential that eye care practitioners are able to provide advice and management options based on quality research evidence.
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Affiliation(s)
- Amy L Sheppard
- School of Life and Health Sciences, Aston University, Birmingham, UK
| | - James S Wolffsohn
- School of Life and Health Sciences, Aston University, Birmingham, UK
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Bartha MC, Allie P, Kokot D, Roe CP. Field observations of display placement requirements and character size for presbyopic and prepresbyopic computer users. Work 2016; 52:329-42. [PMID: 26444933 DOI: 10.3233/wor-152158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Computer users continue to report eye and upper body discomfort even as workstation flexibility has improved. Research shows a relationship between character size, viewing distance, and reading performance. Few reports exist regarding text height viewed under normal office work conditions and eye discomfort. OBJECTIVE This paper reports self-selected computer display placement, text characteristics, and subjective comfort for older and younger computer workers under real-world conditions. METHODS Computer workers were provided with monitors and adjustable display support(s). In Study 1, older workers wearing progressive-addition lenses (PALs) were observed. In study 2, older workers wearing multifocal lenses and younger workers were observed. RESULTS Workers wearing PALs experienced less eye and body discomfort with adjustable displays, and less eye and neck discomfort for text visual angles near or greater than ergonomic recommendations. Older workers wearing multifocal correction positioned displays much lower than younger workers. In general, computer users did not adjust character size to ensure that fovial images of text fell within the recommended range. CONCLUSIONS Ergonomic display placement recommendations should be different for computer users wearing multifocal correction for presbyopia. Ergonomic training should emphasize adjusting text size for user comfort.
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Affiliation(s)
- Michael C Bartha
- Ergonomics R&D Program, Hewlett-Packard Company, Houston, TX, USA
| | - Paul Allie
- Kokot and Allie Associates, LLC, Grand Rapids, MI, USA
| | - Douglas Kokot
- Kokot and Allie Associates, LLC, Grand Rapids, MI, USA
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13
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Long J, Cheung R, Duong S, Paynter R, Asper L. Viewing distance and eyestrain symptoms with prolonged viewing of smartphones. Clin Exp Optom 2016; 100:133-137. [PMID: 27716998 DOI: 10.1111/cxo.12453] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 05/27/2016] [Accepted: 06/04/2016] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND This paper investigates viewing distances and eyestrain symptoms in young adults reading from a smartphone for 60 minutes. METHODS A survey related to common asthenopic (eyestrain) symptoms was administered to subjects before and after they read an extract from a novel on a smartphone for 60 minutes. Subjects rated their symptoms on a scale from zero (not at all) to four (extremely). The viewing distance to the smartphone was measured on a photograph taken of the subject every minute. Each subject used the same smartphone and read the same text. RESULTS Subjects were 18 young adults (mean age: 21.5 ± 3.3 years) with self-reported good health, normal visual acuity and no accommodative or binocular vision disorders. The mean viewing distance while using a smartphone over 60 minutes was 29.2 ± 7.3 cm. The viewing distance was significantly greater during the first, second and fifth 10-minute time periods (30.6 ± 7.2 cm, 29.7 ± 7.3 cm and 28.9 ± 8.5 cm, respectively) than during the final 10-minute time period (27.8 ± 7.7 cm) (Wilcoxon, p = 0.023, 0.02 and 0.04, respectively). The total symptom score was significantly greater post-experiment (score = 8.06) than pre-experiment (score = 3.56) (Wilcoxon, p < 0.001). Symptoms of tired eyes, uncomfortable eyes and blur increased significantly after 60 minutes of smartphone use (Wilcoxon, p < 0.05). There was a significant correlation between change in total symptom score and change in viewing distance (ρ = -0.51; p = 0.03). The only single symptom that correlated with a change in viewing distance was 'uncomfortable eyes' (ρ = -0.52, p = 0.03). CONCLUSION Viewing distances are closer and eyestrain symptoms are greater after reading from a smartphone for 60 minutes. The viewing distances measured were closer than those previously reported in the literature.
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Affiliation(s)
- Jennifer Long
- School of Optometry and Vision Science, The University of New South Wales, Kensington, New South Wales, Australia
| | - Rene Cheung
- School of Optometry and Vision Science, The University of New South Wales, Kensington, New South Wales, Australia
| | - Simon Duong
- School of Optometry and Vision Science, The University of New South Wales, Kensington, New South Wales, Australia
| | - Rosemary Paynter
- School of Optometry and Vision Science, The University of New South Wales, Kensington, New South Wales, Australia
| | - Lisa Asper
- School of Optometry and Vision Science, The University of New South Wales, Kensington, New South Wales, Australia
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Effect of Direct Glare on Orbicularis Oculi and Trapezius During Computer Reading. Optom Vis Sci 2016; 93:738-49. [DOI: 10.1097/opx.0000000000000855] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Abstract
PURPOSE Orbicularis oculi muscle tension and muscle blood flow have been shown to be objective measures of eyestrain during visually demanding activities, such as computer work. In line with this, positive associations between eye-related pain and muscle blood flow in orbicularis oculi have been observed. A hypothesis regarding work situations with cognitive tasks and low-level muscle activity, such as computer work, proposes that muscle pain originates from the blood vessel-nociceptor interactions of the connective tissue of the muscle. Noninvasive muscle blood flow measurements in the orbicularis oculi muscle are preferable to using an invasive technique. The aim of this study was to test reproducibility and stability of muscle blood recordings in orbicularis oculi using photoplethysmography. METHODS In the reproducibility tests, 12 subjects were tested twice within 1 to 5 weeks. To study the stability of the method, six of the subjects were randomly selected and tested four more times within 2 to 6 weeks. Test subjects were doing identical visually demanding computer work for 10 minutes in each test. RESULTS The short-term repeatability of muscle blood flow measurements was considered good, but the stability of blood flow recordings over time in orbicularis oculi was low because of a greater within-subject maximum variability compared with between-subject average variability. CONCLUSIONS Investigators should be aware of the effect of time, possibly attributed to confounding factors such as environmental changes and mental stress, when comparing photoplethysmography muscle blood flow recordings.
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Spontaneous eyeblink activity under different conditions of gaze (eye position) and visual glare. Graefes Arch Clin Exp Ophthalmol 2014; 252:1147-53. [DOI: 10.1007/s00417-014-2673-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 04/30/2014] [Accepted: 05/10/2014] [Indexed: 10/25/2022] Open
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Han CC, Liu R, Liu RR, Zhu ZH, Yu RB, Ma L. Prevalence of asthenopia and its risk factors in Chinese college students. Int J Ophthalmol 2013; 6:718-22. [PMID: 24195055 DOI: 10.3980/j.issn.2222-3959.2013.05.31] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/16/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To determine the prevalence of asthenopia and identify any associated risk factors in the college students in Xi'an, China. METHODS From April to September 2012, 1 500 students from five universities in Xi'an were selected according to a multi-stage stratified cluster sampling method. Data on demographic features, lifestyle or dietary habits, health status, living environment conditions, sleep and mental status, and asthenopia symptoms were collected through a self-administered validated questionnaire. Univariate logistic regression and multivariate logistic regression analysis modified by the factor analysis were performed to evaluate risk factors for asthenopia. RESULTS Fifty-seven percent of the college students complained of asthenopia. Statistically significant risk factors for asthenopia in the univariate analysis included 13 variables. Multivariate analysis revealed a significant relationship between the use of computer and asthenopia (OR 1.21, 95%CI: 1.09 to 1.35). Good sleep and mental status (OR 0.86, 95%CI: 0.76 to 0.97), good living environment conditions (OR 0.67, 95%CI: 0.60 to 0.76), and high intake of green leafy vegetables (OR 0.89, 95%CI: 0.80 to 0.98) were found to be strong predictors of decreasing the occurrence of asthenopia complaints. CONCLUSION Asthenopia symptom appears to be common among college students; and it is strongly associated with computer use, psychosocial state, environment conditions and dietary habits, suggesting that additional studies are warranted to verify these risk factors and establish prevention guidelines, especially for college students.
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Affiliation(s)
- Cheng-Cheng Han
- School of Public Health, Xi'an Jiaotong University College of Medicine, 76 Yanta West Road, Xi'an 710061, Shaanxi Province, China
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Effects of background lighting and retinal illuminance on spontaneous eyeblink activity of human subjects in primary eye gaze. Eye Contact Lens 2013; 39:138-46. [PMID: 23172317 DOI: 10.1097/icl.0b013e31827124b7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To further evaluate possible effects of lighting conditions on the spontaneous eyeblink rate (SEBR) of normal young adult human subjects. METHODS A baseline 5 min video recording was made followed by a second recording under test conditions in 7 different groups of 10 subjects. These test conditions were a simple repeat recording under reference conditions (subjects maintaining silence, with gaze directed towards a target on a 2 m distant whiteboard with the luminance of the reflected light of 35 cd/m, recording under lower (5 cd/m), higher (75 cd/m) and floodlit (150 cd/m) levels, after pupil dilation with phenylephrine 2.5 %, after sudden increase with floodlights (to 200 cd/m), as compared subjects engaged in conversation. RESULTS The overall SEBR values ranged from 8.4 to 15.8 eyeblinks per minute (mean 12.3 ± 2.8 eyeblinks per minute). These did not significantly change with repeated assessments, no significant changes were seen comparing lower or higher illumination levels or after pupil dilation, but an increase to 20.0 ± 4.6 eyeblinks per minute was seen with a sudden increase in illumination. Conversation increased SEBR to 22.2 ± 6.4 eyeblinks per minute. CONCLUSIONS Spontaneous eyeblink activity in silence may be slightly affected by background lighting conditions, but such effects are notably less than SEBR changes that can occur when there is a sudden increase in lighting levels (as a glare stimulus) or when assessments are made during conversation.
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Yang SN, Tai YC, Sheedy JE, Kinoshita B, Lampa M, Kern JR. Comparative effect of lens care solutions on blink rate, ocular discomfort and visual performance. Ophthalmic Physiol Opt 2012; 32:412-20. [DOI: 10.1111/j.1475-1313.2012.00922.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Dolgonos S, Ayyala H, Evinger C. Light-induced trigeminal sensitization without central visual pathways: another mechanism for photophobia. Invest Ophthalmol Vis Sci 2011; 52:7852-8. [PMID: 21896840 DOI: 10.1167/iovs.11-7604] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The authors investigated whether trigeminal sensitization occurs in response to bright light with the retina disconnected from the rest of the central nervous system by optic nerve section. METHODS In urethane-anesthetized rats, trigeminal reflex blinks were evoked with air puff stimuli directed at the cornea in darkness and at three different light intensities. After normative data were collected, the optic nerve was lesioned and the rats were retested. In an alert rat, reflex blinks were evoked by stimulation of the supraorbital branch of the trigeminal nerve in the dark and in the light. RESULTS A 9.1 × 10(3) μW/cm(2) and a 15.1 × 10(3) μW/cm(2) light significantly enhanced the magnitude of reflex blinks relative to blinks evoked by the same trigeminal stimulus when the rats were in the dark. In addition, rats exhibited a significant increase in spontaneous blinking in the light relative to the blink rate in darkness. After lesioning of the optic nerve, the 15.1 × 10(3) μW/cm(2) light still significantly increased the magnitude of trigeminal reflex blinks. CONCLUSIONS Bright lights increase trigeminal reflex blink amplitude and the rate of spontaneous blinking in rodents. Light can modify trigeminal activity without involving the central visual system.
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Affiliation(s)
- Sarah Dolgonos
- School of Medicine, Stony Brook University, Stony Brook, New York 11794-5230, USA
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Nahar NK, Gowrisankaran S, Hayes JR, Sheedy JE. Interactions of visual and cognitive stress. ACTA ACUST UNITED AC 2011; 82:689-96. [PMID: 21885351 DOI: 10.1016/j.optm.2011.07.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 03/23/2011] [Accepted: 07/06/2011] [Indexed: 12/01/2022]
Abstract
BACKGROUND The objective of this research is to assess the ocular and muscular response to long-duration reading under different visual and cognitive difficulty levels. METHODS Thirty-five subjects, with 20/20 vision and without history of ocular pathology or cognitive deficits, participated in the study. Subjects read under different visual and cognitive difficulty levels for 6 (30-minute) conditions. Upper and lower orbicularis oculi, frontalis, and trapezius muscle activities were recorded using surface electromyography (EMG). Aperture size, pupil diameter, and pulse rate of the subjects were recorded with a video camera, pulse meter, and ISCAN eye tracker (ISCAN Inc.), respectively. RESULTS The results show that the texts read with a refractive error caused increased orbicularis oculi EMG power and reduced aperture size (P < 0.001). There was no statistically significant difference between the conditions for pulse rate, pupil diameter, or EMG activity of the frontalis and trapezius muscles with either visual or cognitive stress presented in this experiment. CONCLUSION Visual stress experienced due to reading under an induced refractive error is potentially mediated by a local mechanism, different from the mechanism underlying reading under low contrast or high cognitive demand.
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Affiliation(s)
- Niru K Nahar
- The Ohio State University, College of Optometry, Columbus, USA.
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O'Hare L, Hibbard PB. Spatial frequency and visual discomfort. Vision Res 2011; 51:1767-77. [PMID: 21684303 DOI: 10.1016/j.visres.2011.06.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 05/27/2011] [Accepted: 06/03/2011] [Indexed: 11/16/2022]
Affiliation(s)
- Louise O'Hare
- School of Psychology, University of St. Andrews, St. Mary's Quad, South Street, St. Andrews, Fife KY16 9JP, United Kingdom.
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Suh YW, Kim KH, Kang SY, Kim SW, Oh JR, Kim HM, Song JS. The Objective Methods to Evaluate Ocular Fatigue Associated With Computer Work. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2010. [DOI: 10.3341/jkos.2010.51.10.1327] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Young-Woo Suh
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Kyun-Hyung Kim
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Gachon University Gil Medical Center, Incheon, Korea
| | - Su-Yeon Kang
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Seoung Woo Kim
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Jae Ryung Oh
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Hyo-Myung Kim
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Jong-Suk Song
- The Association for Research in Visual Function, Korea University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
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