Ergonomic benefit using heads-up display compared to conventional surgical microscope in Japanese ophthalmologists.

PURPOSE: Occupational musculoskeletal disorders are prevalent in ophthalmic surgeons and can impact surgeons' well-being and productivity. Heads-up displays may reduce ergonomic stress compared to conventional microscopes. This cross-sectional, non-interventional study compared ergonomic experience between heads-up display and conventional ocular microscopes. METHODS: The study protocol was approved by the independent ethics committee and nonprofit organization MINS Institutional Review Board. An online questionnaire was distributed to a sample of ophthalmic surgeons in Japan with experience operating with heads-up display. The questionnaire captured surgeon-specific variables, the standardized Nordic Musculoskeletal Questionnaire, and custom questions to compare heads-up display and conventional microscope and understand long-term impacts of musculoskeletal disorders. RESULTS: Analysis was conducted on responses from 67 surgeons with a mean 25 years of practice and 2.7 years using heads-up display. Many surgeons agreed or strongly agreed that heads-up display reduced the severity (40%) and frequency (40%) of pain and discomfort, improved posture (61%), and improved overall comfort (61%). Of respondents who experienced asthenopia (n = 59) or pain/discomfort during operation (n = 61), 54% reported improvement in asthenopia and 72% reported feeling less pain/discomfort since using heads-up display. Overall, 69% reported preference for heads-up display. CONCLUSION: This study provides novel data on musculoskeletal disorders and the long-term impacts of ergonomic strain reported by ophthalmologists building on existing literature demonstrating ergonomic and other advantages of heads-up display. Future studies with objective ergonomic assessment are warranted to validate these findings.

Visualisation ergonomics and robotic surgery.

Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon camera control, and line of sight screen location. Other ergonomic factors relating to visualisation include stereo-acuity, vergence-accommodation mismatch, visual-perception mismatch, visual-vestibular mismatch, visuospatial ability, visual fatigue, and visual feedback to compensate for lack of haptic feedback. Visual fatigue symptoms may be related to dry eye or accommodative/binocular vision stress. Digital eye strain can be measured by questionnaires and objective tests. Management options include treatment of dry eye, correction of refractive error, and management of accommodation and vergence anomalies. Experienced robotic surgeons can use visual cues like tissue deformation and surgical tool information as surrogates for haptic feedback.

Does the smartphone's eye protection mode work?

People spend about 5-8 hours per day on phones, causing circadian disruption and eye fatigue, thus raising a great need for comfort and health. Most phones have eye protection modes, claiming a potential eye protection effect. To examine the effectiveness, we investigated the color quality, namely gamut area and just noticeable color difference (JNCD), and circadian effect, namely equivalent melanopic lux (EML) and melanopic daylight efficacy ratio (MDER), characteristics of two smartphones: iPhone 13 and HUAWEI P30, in normal and eye protection mode. The results show that the circadian effect is inversely proportional to color quality when the iPhone 13 and HUAWEI P30 changed from normal to eye protection mode. The gamut area changed from 102.51% to 82.5% sRGB and 100.36% to 84.55% sRGB, respectively. The EML and MDER decreased by 13 and 15, and, 0.50 and 0.38, respectively, affected by the eye protection mode and screen luminance. The EML and JNCD results in different modes show that the eye protection mode benefits the nighttime circadian effect at the cost of the image quality. This study provides a way to precisely assess the image quality and circadian effect of displays and elucidates the tradeoff relationship between them.

Anti-Fatigue Glasses Based on Microprisms for Preventing Eyestrain.

Although microprisms have become an important medical means of strabismus treatment, related research concerning the design, fabrication, and testing of microprismatic glasses for preventing eyestrain has rarely been reported. In this study, the structure of microprismatic glasses for preventing eyestrain related to using electronic monitors, including computers and mobile phones, is introduced. A designing theory of anti-fatigue glasses with microprisms is developed. The fabrication technique and the process are described, and the performances of the fabricated microprisms are characterized. Finally, a compact testing system for the measurement of prismatic diopter is designed and constructed. This measuring system can be used not only for Fresnel microprisms, but also for other types of prisms. The measured results agree with our calculations. Although this study is focused on optimizing the objective prismatic diopter for anti-fatigue microprismatic glasses, 2.0-3.0 prismatic diopters (Δ) for each eye in the anti-fatigue glasses are suggested according to our experience on strabismus treatments. The clinical research for patients using the developed anti-fatigue glasses will be fully implemented in our further research to confirm the optimal subjective prismatic value.

Computer vision syndrome, visual ergonomics and amelioration among staff members in a Saudi medical college.

Objectives. Nearly 60 million people suffer from computer vision syndrome (CVS) globally, resulting in reduced work productivity. This study aimed to determine the prevalence of CVS, describe the working conditions, visualize ergonomic factors and determine preventive measures application among university staff members. Methods. A cross-sectional study was conducted with university medical staff members using a semi-structured questionnaire that included a validated CVS questionnaire. Results. CVS prevalence was 81.2%. Dryness, headache, feeling that sight is worsening and difficulty in focusing on near vision were the most experienced symptoms. Prevalence of CVS was significantly higher among females (52.3%), those having a higher mean work duration (21.65 ± 7.55 years), those who frequently use a smartphone (84.9%) and those spending most of their screen time during both day and night (87.1%). Visual ergonomics and preventive measures application, such as correct screen level, regular cleaning of the screen, appropriate illumination and use of eye drops, were significantly associated with negative CVS. Conclusions. These results raised attention to the essential need for visual assessment of university staff members for early and proper diagnosis of CVS to minimize its impact on working performance. Accordingly, it is recommended to organize university-based awareness programs regarding CVS for working personnel.

Digital asthenopia: blue-blocking lenses and + 0,40D additional power in the near zone, for eye strain, accommodation and convergence functions / Astenopia digital: avaliação de lentes com filtro de luz azul e poder adicional de +0,40D na zona de perto, para fadiga visual e nas funções de convergência e acomodação

ABSTRACT Purpose Evaluate blue-violet light filter and additional power of +0.40 D in the near zone ophthalmic lenses, on convergence, accommodative functions, and symptoms of digital asthenopia (DA). Methods Randomized study in cross-over design conducted on 49 volunteers (age, 29 ± 5.5 years; male: female, 18:31). Each subject wore test (+0.40 D in the near zone) and control lenses (regular single vision) for 4 weeks in randomized order. Both lenses had a selective blue-violet light filter. A baseline measurement was taken with the subjects' current updated glasses. Accommodation amplitude (AA) and near point of convergence (NPC) were measured binocularly with the RAF ruler. DA was evaluated by a questionnaire. Results No significant difference (p=.52) was found for AA comparing baseline (11.50±1.88 D), test (11.61± 1.62 D), and control SV lenses (11.88±1.50 D). No significant difference was found for NPC (p=.94), between baseline (6.50 ± 2.89cm), test (6.71± 3.49) and control SV lenses (6.82± 3.50 cm). No significant difference was found comparing test and control SV lenses in symptoms of DA (p=0.20). Conclusions The +0.40 D lenses have no negative impact on convergence or loss of accommodation power. The +0.40 D and control SV lenses had a similar impact on attenuating symptoms of DA.

RESUMO Objetivo Avaliar os efeitos do uso de lentes oftálmicas com filtro seletivo de luz azul-violeta, sem e com poder adicional de + 0,4D na zona de perto nas funções de acomodação e convergência e para sintomas de astenopia digital (AD). Métodos Ensaio clínico controlado, randomizado e mascarado, com 49 voluntários (idade, 29 ± 5,5 anos; masculino: feminino, 18: 31). Cada participante usou lentes de teste (+0,40 D na zona de perto) e controle (visão simples), por 4 semanas de forma randomizada. Ambas as lentes tinham filtro seletivo de luz azul-violeta. A medição inicial (baseline) foi feita com os óculos atualizados de cada participante. A amplitude de acomodação (AA) e o ponto de convergência próximo (PPC) foram medidos binocularmente com a régua RAF. A AD foi avaliada por um questionário. Resultados Não houve diferença estatisticamente significante (p=0,52) para as medidas de AA comparando as lentes baseline (11,50±1,88 D), teste (11,61±1,62 D) e controle VS (11,88±1,50 D). Nenhuma diferença significativa foi encontrada para a medida do PPC (p=0,94), entre as lentes baseline (6,50 ± 2,89cm), teste (6,71±3,49) e controle VS (6,82±3,50 cm). Nenhuma diferença significativa foi encontrada comparando lentes teste de VS e controle nos sintomas de AD (p=0,20). Conclusões As lentes com +0,40 D não têm impacto negativo na convergência ou na perda de acomodação. As lentes +0,40 D e controle VS, tiveram impacto semelhante na redução dos sintomas de AD.

A Peer-to-Peer Live-Streaming Intervention for Children During COVID-19 Homeschooling to Promote Physical Activity and Reduce Anxiety and Eye Strain: Cluster Randomized Controlled Trial.

BACKGROUND: The COVID-19 pandemic has led to worldwide school closures, with millions of children confined to online learning at home. As a result, children may be susceptible to anxiety and digital eye strain, highlighting a need for population interventions. OBJECTIVE: The objective of our study was to investigate whether a digital behavior change intervention aimed at promoting physical activity could reduce children's anxiety and digital eye strain while undergoing prolonged homeschooling during the COVID-19 pandemic. METHODS: In this cluster randomized controlled trial, homeschooled grade 7 students at 12 middle schools in southern China were recruited through local schools and randomly assigned by the school to receive (1:1 allocation): (1) health education information promoting exercise and ocular relaxation, and access to a digital behavior change intervention, with live streaming and peer sharing of promoted activities (intervention), or (2) health education information only (control). The primary outcome was change in self-reported anxiety score. Secondary outcomes included change in self-reported eye strain and sleep quality. RESULTS: On March 16, 2020, 1009 children were evaluated, and 954 (94.5%) eligible children of consenting families were included in the intention-to-treat analysis. Children in the intervention (n=485, 6 schools) and control (n=469, 6 schools) groups were aged 13.5 (SD 0.5) years, and 52.3% (n=499) were male. The assigned interventions were completed by 896 children (intervention: n=467, 96.3%; control: n=429, 91.5%). The 2-week change in square-root-transformed self-reported anxiety scores was greater in the intervention (-0.23, 95% CI -0.27 to -0.20) vs control group (0.12, 95% CI 0.09-0.16; unadjusted difference -0.36, 95% CI -0.63 to -0.08; P=.02). There was a significant reduction in square-root-transformed eye strain in the intervention group (-0.08, 95% CI -0.10 to 0.06) compared to controls (0.07, 95% CI 0.05-0.09; difference -0.15, 95% CI -0.26 to -0.03; P=.02). Change in sleep quality was similar between the two groups. CONCLUSIONS: This digital behavior change intervention reduced children's anxiety and eye strain during COVID-19-associated online schooling. TRIAL REGISTRATION: ClinicalTrials.gov NCT04309097; http://clinicaltrials.gov/ct2/show/NCT04309097.

Design Guidelines of a Computer-Based Intervention for Computer Vision Syndrome: Focus Group Study and Real-World Deployment.

BACKGROUND: Prolonged time of computer use increases the prevalence of ocular problems, including eye strain, tired eyes, irritation, redness, blurred vision, and double vision, which are collectively referred to as computer vision syndrome (CVS). Approximately 70% of computer users have vision-related problems. For these reasons, properly designed interventions for users with CVS are required. To design an effective screen intervention for preventing or improving CVS, we must understand the effective interfaces of computer-based interventions. OBJECTIVE: In this study, we aimed to explore the interface elements of computer-based interventions for CVS to set design guidelines based on the pros and cons of each interface element. METHODS: We conducted an iterative user study to achieve our research objective. First, we conducted a workshop to evaluate the overall interface elements that were included in previous systems for CVS (n=7). Through the workshop, participants evaluated existing interface elements. Based on the evaluation results, we eliminated the elements that negatively affect intervention outcomes. Second, we designed our prototype system LiquidEye that includes multiple interface options (n=11). Interface options included interface elements that were positively evaluated in the workshop study. Lastly, we deployed LiquidEye in the real world to see how the included elements affected the intervention outcomes. Participants used LiquidEye for 14 days, and during this period, we collected participants' daily logs (n=680). Additionally, we conducted prestudy and poststudy surveys, and poststudy interviews to explore how each interface element affects participation in the system. RESULTS: User data logs collected from the 14 days of deployment were analyzed with multiple regression analysis to explore the interface elements affecting user participation in the intervention (LiquidEye). Statistically significant elements were the instruction page of the eye resting strategy (P=.01), goal setting of the resting period (P=.009), compliment feedback after completing resting (P<.001), a mid-size popup window (P=.02), and CVS symptom-like effects (P=.004). CONCLUSIONS: Based on the study results, we suggested design implications to consider when designing computer-based interventions for CVS. The sophisticated design of the customization interface can make it possible for users to use the system more interactively, which can result in higher engagement in managing eye conditions. There are important technical challenges that still need to be addressed, but given the fact that this study was able to clarify the various factors related to computer-based interventions, the findings are expected to contribute greatly to the research of various computer-based intervention designs in the future.

Do Blue-blocking Lenses Reduce Eye Strain From Extended Screen Time? A Double-Masked Randomized Controlled Trial.

PURPOSE: To investigate if blue-blocking lenses are effective in reducing the ocular signs and symptoms of eye strain associated with computer use. DESIGN: Double-masked, randomized controlled trial. METHODS: A total of 120 symptomatic computer users were randomly assigned (1:1) into a "positive" or "negative" advocacy arm (ie, a clinician either advocating or not advocating for the intervention via a prerecorded video). Participants were further sub-randomized (1:1) to receive either clear (placebo) or blue-blocking spectacles. All participants were led to believe they had received an active intervention. Participants performed a 2-hour computer task while wearing their assigned spectacle intervention. The prespecified primary outcome measures were the mean change (post- minus pre-computer task) in eye strain symptom score and critical flicker-fusion frequency (CFF, an objective measure of eye strain). The study also investigated whether clinician advocacy of the intervention (in a positive or negative light) modulated clinical outcomes. RESULTS: All participants completed the study. In the primary analysis, for CFF, no significant effect was found for advocacy type (positive or negative, p = .164) and spectacle intervention type (blue-blocking or clear lens, p = .304). Likewise, for eye strain symptom score, no differences were found for advocacy (p = .410) or spectacle lens types (p = .394). No adverse events were documented. CONCLUSIONS: Blue-blocking lenses did not alter signs or symptoms of eye strain with computer use relative to standard clear lenses. Clinician advocacy type had no bearing on clinical outcomes.

A double-blind test of blue-blocking filters on symptoms of digital eye strain.

BACKGROUND: Many ophthalmic lens manufacturers are currently marketing blue-blocking filters, which they claim will reduce symptoms of Digital Eye Strain (DES). However, there is limited evidence to support the proposal that DES results from the blue light emitted by electronic screens. OBJECTIVE: This investigation compared the effect of blue-blocking filters on DES symptoms with a no-filter lens, using a double-blind methodology. METHODS: Twenty-four subjects were required to perform a 20-minute reading task from a tablet computer. They wore either lenses containing a blue-blocking filter (TheraBlue 1.67 or TheraBlue polycarbonate) or a CR-39 control lens which did not include a filter. Immediately following each session, subjects completed a questionnaire to quantify symptoms of DES. RESULTS: While a significant increase in symptoms was observed immediately following the near vision task (p = 0.00001), no significant difference in symptoms was found between the 3 lens conditions (p = 0.74). CONCLUSIONS: There is little evidence at this time to support the use of blue-blocking filters as a clinical treatment for DES. Management of other ocular factors, as well as the creation of an optimal environment for screen viewing, are more likely to provide greater success in minimizing symptoms.

Comparison of Visual Stimuli for Steady-State Visual Evoked Potential-Based Brain-Computer Interfaces in Virtual Reality Environment in terms of Classification Accuracy and Visual Comfort.

Recent studies on brain-computer interfaces (BCIs) based on the steady-state visual evoked potential (SSVEP) have demonstrated their use to control objects or generate commands in virtual reality (VR) environments. However, most SSVEP-based BCI studies performed in VR environments have adopted visual stimuli that are typically used in conventional LCD environments without considering the differences in the rendering devices (head-mounted displays (HMDs) used in the VR environments). The proximity between the visual stimuli and the eyes in HMDs can readily cause eyestrain, degrading the overall performance of SSVEP-based BCIs. Therefore, in the present study, we have tested two different types of visual stimuli-pattern-reversal checkerboard stimulus (PRCS) and grow/shrink stimulus (GSS)-on young healthy participants wearing HMDs. Preliminary experiments were conducted to investigate the visual comfort of each participant during the presentation of the visual stimuli. In subsequent online avatar control experiments, we observed considerable differences in the classification accuracy of individual participants based on the type of visual stimuli used to elicit SSVEP. Interestingly, there was a close relationship between the subjective visual comfort score and the online performance of the SSVEP-based BCI: most participants showed better classification accuracy under visual stimulus they were more comfortable with. Our experimental results suggest the importance of an appropriate visual stimulus to enhance the overall performance of the SSVEP-based BCIs in VR environments. In addition, it is expected that the appropriate visual stimulus for a certain user might be readily selected by surveying the user's visual comfort for different visual stimuli, without the need for the actual BCI experiments.

See-Through Type 3D Head-Mounted Display-Based Surgical Microscope System for Microsurgery: A Feasibility Study.

BACKGROUND: The surgical microscope is used primarily for microsurgeries, which are more complicated than other surgical procedures and require delicate tasks for a long time. Therefore, during these surgical procedures, surgeons experience back and neck pain. To solve this problem, new technology, such as wearable displays, is required to help surgeons maintain comfortable postures and enjoy advanced functionality during microsurgery. OBJECTIVE: The objective of this study was to develop a surgical microscope system that would work with wearable devices. It would include a head-mounted display (HMD) that can offer 3D surgical images and allow a flexible and comfortable posture instead of fixed eyepieces of surgical microscope and can also provide peripheral visual field with its optical see-through function. METHODS: We designed and fabricated a surgical microscope system that incorporates a see-through type 3D HMD, and we developed an image processing software to provide better image quality. The usability of the proposed system was confirmed with preclinical examination. Seven ENT (ear, nose, and throat) surgical specialists and 8 residents performed a mock surgery-axillary lymph node dissection on a rat. They alternated between looking through the eyepieces of the surgical microscope and viewing a 3D HMD screen connected to the surgical microscope. We examined the success of the surgery and asked the specialists and residents to grade eye fatigue on a scale of 0 (none) to 6 (severe) and posture discomfort on a scale of 1 (none) to 5 (severe). Furthermore, a statistical comparison was performed using 2-tailed paired t test, and P=.00083 was considered significant. RESULTS: Although 3D HMD case showed a slightly better result regarding visual discomfort (P=.097), the average eye fatigue was not significantly different between eyepiece and 3D HMD cases (P=.79). However, the average posture discomfort, especially in neck and shoulder, was lower with 3D HMD display use than with eyepiece use (P=.00083). CONCLUSIONS: We developed a see-through type 3D HMD-based surgical microscope system and showed through preclinical testing that the system could help reduce posture discomfort. The proposed system, with its advanced functions, could be a promising new technique for microsurgery.

Blue-blocking Filters and Digital Eyestrain.

SIGNIFICANCE: Many manufacturers are currently marketing blue-blocking (BB) filters, which they claim will reduce the symptoms of digital eyestrain (DES). However, there is limited evidence to support the proposal that DES results from the blue light emitted by these devices. PURPOSE: The visual and ocular symptoms commonly experienced when viewing digital screens are collectively termed DES. The emission spectrum of modern digital displays frequently includes a high percentage of blue light. Being higher in energy, these short wavelengths may contribute to DES. This study examined the effect of a BB filter on symptoms of DES during a sustained near-vision task. METHODS: Twenty-three young, visually normal subjects were required to perform a 30-minute reading task from a tablet computer. The digital screen was overlaid with either a BB or neutral-density (ND) filter producing equal screen luminance. During each session, the accommodative response, pupil diameter, and vertical palpebral aperture dimension were measured at 0, 9, 19, and 29 minutes after the start of the reading task. Immediately following each session, subjects completed a questionnaire to quantify symptoms of DES. RESULTS: The BB filter blocked 99% of the wavelengths between 400 and 500 nm. The mean total symptom scores (±1 SEM) for the BB and ND filter conditions were 42.83 (3.58) and 42.61 (3.17), respectively (P = .62). No significant differences in accommodation or vertical palpebral aperture dimension were observed between the two filter conditions, although the magnitude of the mean accommodative response did increase significantly during the first 9 minutes of the task (P = .02). CONCLUSIONS: A filter that eliminated 99% of the emitted blue light was no more effective at reducing symptoms of DES than an equiluminant ND filter. There is little evidence at this time to support the use of BB filters to minimize near work-induced asthenopia.

A Randomized, Placebo-Controlled Study on the Safety and Efficacy of Daily Ingestion of Green Tea (Camellia sinensis L.) cv. "Yabukita" and "Sunrouge" on Eyestrain and Blood Pressure in Healthy Adults.

The green tea (Camellia sinensis L.) cultivar “Sunrouge” contains anthocyanins, catechins and flavonols. To determine whether ingesting green tea containing anthocyanins improves visual function and blood pressure (BP) in healthy adults, a randomized, double-blind, placebo-controlled study was performed. A total of 120 healthy subjects, aged between 20 and 60 years and with a systolic BP (SBP) value of ≤125 and <155 and a diastolic BP (DBP) value <95, or a DBP of ≤75 mmHg and <95 mmHg and a SBP <155 mmHg, were randomly assigned to one of three groups. For 12 weeks, the placebo group received barley extract without catechin; another group received “Sunrouge” extract containing 11.2 mg anthocyanin and 323.6 mg epigallocatechin-3-O-gallate (EGCG); and a third group received “Yabukita” extract containing 322.2 mg EGCG. Home BP, accommodation ability, visual analog scale questionnaires for eyestrain, and metabolic-associated markers were analyzed at weeks 0, 4, 8, and 12 of the intake period. The ingestion of “Sunrouge” tea significantly improved accommodation ability and eyestrain in subjects younger than 45 years and in subjects who operated visual display terminals every day. It also elevated BP. “Yabukita” tea ingestion significantly increased serum adiponectin levels. No adverse effects were observed. We conclude that long-term intake of “Sunrouge” tea containing anthocyanins and flavonols might improve visual function.

Optical correction of refractive error for preventing and treating eye symptoms in computer users.

BACKGROUND: Computer users frequently complain about problems with seeing and functioning of the eyes. Asthenopia is a term generally used to describe symptoms related to (prolonged) use of the eyes like ocular fatigue, headache, pain or aching around the eyes, and burning and itchiness of the eyelids. The prevalence of asthenopia during or after work on a computer ranges from 46.3% to 68.5%. Uncorrected or under-corrected refractive error can contribute to the development of asthenopia. A refractive error is an error in the focusing of light by the eye and can lead to reduced visual acuity. There are various possibilities for optical correction of refractive errors including eyeglasses, contact lenses and refractive surgery. OBJECTIVES: To examine the evidence on the effectiveness, safety and applicability of optical correction of refractive error for reducing and preventing eye symptoms in computer users. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; Embase; Web of Science; and OSH update, all to 20 December 2017. Additionally, we searched trial registries and checked references of included studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-randomised trials of interventions evaluating optical correction for computer workers with refractive error for preventing or treating asthenopia and their effect on health related quality of life. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study eligibility and risk of bias, and extracted data. Where appropriate, we combined studies in a meta-analysis. MAIN RESULTS: We included eight studies with 381 participants. Three were parallel group RCTs, three were cross-over RCTs and two were quasi-randomised cross-over trials. All studies evaluated eyeglasses, there were no studies that evaluated contact lenses or surgery. Seven studies evaluated computer glasses with at least one focal area for the distance of the computer screen with or without additional focal areas in presbyopic persons. Six studies compared computer glasses to other types of glasses; and one study compared them to an ergonomic workplace assessment. The eighth study compared optimal correction of refractive error with the actual spectacle correction in use. Two studies evaluated computer glasses in persons with asthenopia but for the others the glasses were offered to all workers regardless of symptoms. The risk of bias was unclear in five, high in two and low in one study. Asthenopia was measured as eyestrain or a summary score of symptoms but there were no studies on health-related quality of life. Adverse events were measured as headache, nausea or dizziness. Median asthenopia scores at baseline were about 30% of the maximum possible score.Progressive computer glasses versus monofocal glassesOne study found no considerable difference in asthenopia between various progressive computer glasses and monofocal computer glasses after one-year follow-up (mean difference (MD) change scores 0.23, 95% confidence interval (CI) -5.0 to 5.4 on a 100 mm VAS scale, low quality evidence). For headache the results were in favour of progressive glasses.Progressive computer glasses with an intermediate focus in the upper part of the glasses versus other glassesIn two studies progressive computer glasses with intermediate focus led to a small decrease in asthenopia symptoms (SMD -0.49, 95% CI -0.75 to -0.23, low-quality evidence) but not in headache score in the short-term compared to general purpose progressive glasses. There were similar small decreases in dizziness. At medium term follow-up, in one study the effect size was not statistically significant (SMD -0.64, 95% CI -1.40 to 0.12). The study did not assess adverse events.Another study found no considerable difference in asthenopia between progressive computer glasses and monofocal computer glasses after one-year follow-up (MD change scores 1.44, 95% CI -6.95 to 9.83 on a 100 mm VAS scale, very low quality evidence). For headache the results were inconsistent.Progressive computer glasses with far-distance focus in the upper part of the glasses versus other glassesOne study found no considerable difference in number of persons with asthenopia between progressive computer glasses with far-distance focus and bifocal computer glasses after four weeks' follow-up (OR 1.00, 95% CI 0.40 to 2.50, very low quality evidence). The number of persons with headache, nausea and dizziness was also not different between groups.Another study found no considerable difference in asthenopia between progressive computer glasses with far-distance focus and monofocal computer glasses after one-year follow-up (MD change scores -1.79, 95% CI -11.60 to 8.02 on a 100 mm VAS scale, very low quality evidence). The effects on headaches were inconsistent.One study found no difference between progressive far-distance focus computer glasses and trifocal glasses in effect on eyestrain severity (MD -0.50, 95% CI -1.07 to 0.07, very low quality evidence) or on eyestrain frequency (MD -0.75, 95% CI -1.61 to 0.11, very low quality evidence).Progressive computer glasses versus ergonomic assessment with habitual (computer) glassesOne study found that computer glasses optimised for individual needs reduced asthenopia sum score more than an ergonomic assessment and habitual (computer) glasses (MD -8.9, 95% CI -16.47 to -1.33, scale 0 to 140, very low quality evidence) but there was no effect on the frequency of eyestrain (OR 1.08, 95% CI 0.38 to 3.11, very low quality evidence).We rated the quality of the evidence as low or very low due to risk of bias in the included studies, inconsistency in the results and imprecision. AUTHORS' CONCLUSIONS: There is low to very low quality evidence that providing computer users with progressive computer glasses does not lead to a considerable decrease in problems with the eyes or headaches compared to other computer glasses. Progressive computer glasses might be slightly better than progressive glasses for daily use in the short term but not in the intermediate term and there is no data on long-term follow-up. The quality of the evidence is low or very low and therefore we are uncertain about this conclusion. Larger studies with several hundreds of participants are needed with proper randomisation, validated outcome measurement methods, and longer follow-up of at least one year to improve the quality of the evidence.

A Systematic Review of Fatigue in Radiology: Is It a Problem?

OBJECTIVE: The purpose of this study was to review current literature regarding radiologist fatigue. MATERIALS AND METHODS: A literature search was performed using PubMed. Key words and Medical Subject Heading terms were used to generate refined queries with inclusion and exclusion criteria, focusing on fatigue and error. Results were selected according to these criteria: examined radiologist fatigue and radiologic error stemming from fatigue; experimental results measured as accuracy, error, or performance; and peer-reviewed publication. The risk of bias was addressed by including both quantitative and qualitative studies. RESULTS: Twenty-seven articles were included, mainly primary research articles. Common outcome measures included subjective self-reports and tests to measure eyestrain. Reaction time was also recorded, accounting for variables such as age and experience. One group recommended that guidelines should be implemented regarding number of hours worked. Most recommended ergonomic interventions, proposing the implementation of tools to measure and standardize fatigue and optimize workflow, in conjunction with considering radiologists individually. Education in appropriate viewing habits and breaks were also suggested. Only one study with seven participants recommended that radiologists should sleep well to improve their performance and overall well-being, despite the undeniable evidence that radiologists are fatigued. CONCLUSION: Fatigue is present in radiology and affects diagnostic accuracy.

The impact of different lenses on visual and musculoskeletal complaints in VDU workers with work-related neck complaints: a randomized controlled trial.

OBJECTIVES: The impact of wearing lenses on visual and musculoskeletal complaints in VDU workers is currently unknown. The goal of this study was 1) to evaluate the impact of wearing VDU lenses on visual fatigue and self-reported neck pain and disability, compared to progressive lenses, and 2) to measure the effect of both lenses on head inclination and pressure pain thresholds during the performance of a VDU task. METHODS: Thirty-five eligible subjects were randomly assigned to wear progressive VDU lenses (VDU group) (n = 18) or progressive lenses (P group) (n = 17). They were enquired about visual complaints (VFQ), self-perceived pain (NRS) and disability (NDI) at baseline (with old lenses), and 1 week, 3 months and 6 months after wearing their new lenses. In addition, Forward Head Angle (FHA) and PPTs were assessed during and after a VDU task before and 6 months after wearing the new lenses. A short questionnaire concerning the satisfaction about the study lenses was completed at the end of the study. RESULTS: In both groups, visual fatigue and neck pain was decreased at 3 and 6 months follow up, compared to baseline. All PPTs were higher during the second VDU task, independent of the type of lenses. The VDU group reported a significantly higher suitability of the lenses for VDU work. CONCLUSION: It can be concluded that there is little difference in effect of the different lenses on visual and musculoskeletal comfort. Lenses should be adjusted to the task-specific needs and habits of the participant.

Tired in the Reading Room: The Influence of Fatigue in Radiology.

Commonly conflated with sleepiness, fatigue is a distinct multidimensional condition with physical and mental effects. Fatigue in health care providers and any secondary effects on patient care are an important societal concern. As medical image interpretation is highly dependent on visual input, visual fatigue is of particular interest to radiologists. Humans analyze their surroundings with rapid eye movements called saccades, and fatigue decreases saccadic velocity. Oculomotor parameters may, therefore, be an objective and reproducible metric of fatigue and eye movement analysis can provide valuable insight into the etiology of fatigue-related error.

A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter / Revisión sistemática de los ensayos controlados sobre estrés visual utilizando filtros intuitivos o colorímetros

Claims that coloured filters aid reading date back 200 years and remain controversial. Some claims, for example, that more than 10% of the general population and 50% of people with dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications with such claims typically cite research using methods that have not been described in the scientific literature and lack a sound aetiological framework. Notwithstanding these criticisms, some researchers have used more rigorous selection criteria and methods of prescribing coloured filters that were developed at a UK Medical Research Council unit and which have been fully described in the scientific literature. We review this research and disconfirm many of the more extreme claims surrounding this topic. This literature indicates that a minority subset of dyslexics (circa 20%) may have a condition described as visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters have been shown to improve reading performance in people with visual stress, but are unlikely to influence the phonological and memory deficits associated with dyslexia and therefore are not a treatment for dyslexia. This review concludes that larger and rigorous randomised controlled trials of interventions for visual stress are required. Improvements in the diagnosis of the condition are also a priority (AU)

Las aseveraciones acerca de que los filtros coloreados ayudan a la lectura se remontan 200 años atrás, y siguen siendo controvertidas. Por ejemplo, algunas afirmaciones relativas a que el 10% de la población general y el 50% de las personas disléxicas podrían beneficiarse de los filtros coloreados carecen de evidencia y de validez firmes. Las publicaciones que incluyen dichas afirmaciones citan, normalmente, investigaciones que hacen uso de métodos no descritos en la literatura científica y que carecen de marcos etiológicos sólidos. A pesar de estas críticas, algunos investigadores han utilizado unos criterios y métodos de selección más rigurosos para la prescripción de filtros coloreados, desarrollados en una unidad del Medical Research Council del Reino Unido y que se han descrito cuidadosamente en la literatura científica. Revisamos todas estas investigaciones que desmienten muchas de las aseveraciones más extremas que rodean a esta cuestión. Esta literatura científica consistente indica que un subgrupo minoritario de disléxicos (de alrededor del 20%) puede padecer una afección médica descrita como estrés visual, que deriva muy probablemente de la hiperexcitabilidad de la corteza visual. El estrés visual se caracteriza por síntomas de distorsión de la percepción visual, cefaleas, y fatiga visual al visualizar patrones repetitivos, incluyendo las líneas de texto. Esta revisión indica que el estrés visual es diferente a la dislexia, aunque a veces coexisten ambas situaciones. Se ha demostrado que los filtros coloreados individualmente prescritos mejoran el desempeño lector en personas con estrés visual, pero es improbable que mejoren los déficits fonológicos y de memoria que se asocian a la dislexia, por lo que no constituyen un tratamiento para la misma. Esta revisión concluye que se precisan más ensayos controlados y aleatorizados sobre intervenciones para el estrés visual. También son prioritarias las mejoras diagnósticas de dicha afección (AU)