Asthenopia

BackgroundComputer vision syndrome (CVS) is a group of visual symptoms experienced in relation to the use of computers. Nearly 60 million people suffer from CVS globally, resulting in reduced productivity at work and reduced quality of life of the computer worker. The present study aims to describe the prevalence of CVS and its associated factors among a nationally-representative sample of Sri Lankan computer workers.MethodsTwo thousand five hundred computer office workers were invited for the study from all nine provinces of Sri Lanka between May and December 2009. A self-administered questionnaire was used to collect socio-demographic data, symptoms of CVS and its associated factors. A binary logistic regression analysis was performed in all patients with 'presence of CVS' as the dichotomous dependent variable and age, gender, duration of occupation, daily computer usage, pre-existing eye disease, not using a visual display terminal (VDT) filter, adjusting brightness of screen, use of contact lenses, angle of gaze and ergonomic practices knowledge as the continuous/dichotomous independent variables. A similar binary logistic regression analysis was performed in all patients with 'severity of CVS' as the dichotomous dependent variable and other continuous/dichotomous independent variables.ResultsSample size was 2210 (response rate-88.4%). Mean age was 30.8 ± 8.1 years and 50.8% of the sample were males. The 1-year prevalence of CVS in the study population was 67.4%. Female gender (OR: 1.28), duration of occupation (OR: 1.07), daily computer usage (1.10), pre-existing eye disease (OR: 4.49), not using a VDT filter (OR: 1.02), use of contact lenses (OR: 3.21) and ergonomics practices knowledge (OR: 1.24) all were associated with significantly presence of CVS. The duration of occupation (OR: 1.04) and presence of pre-existing eye disease (OR: 1.54) were significantly associated with the presence of 'severe CVS'.ConclusionsSri Lankan computer workers had a high prevalence of CVS. Female gender, longer duration of occupation, higher daily computer usage, pre-existing eye disease, not using a VDT filter, use of contact lenses and higher ergonomics practices knowledge all were associated with significantly with the presence of CVS. The factors associated with the severity of CVS were the duration of occupation and presence of pre-existing eye disease.

The mass digitization of books is changing the way information is created, disseminated and displayed. Electronic book readers (e-readers) generally refer to two main display technologies: the electronic ink (E-ink) and the liquid crystal display (LCD). Both technologies have advantages and disadvantages, but the question whether one or the other triggers less visual fatigue is still open. The aim of the present research was to study the effects of the display technology on visual fatigue. To this end, participants performed a longitudinal study in which two last generation e-readers (LCD, E-ink) and paper book were tested in three different prolonged reading sessions separated by--on average--ten days. Results from both objective (Blinks per second) and subjective (Visual Fatigue Scale) measures suggested that reading on the LCD (Kindle Fire HD) triggers higher visual fatigue with respect to both the E-ink (Kindle Paperwhite) and the paper book. The absence of differences between E-ink and paper suggests that, concerning visual fatigue, the E-ink is indeed very similar to the paper.

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.

BackgroundThis meta-analysis aims to determine the clinical manifestations, prevalence, and risk factors of asthenopia across diverse populations.MethodsWe systematically searched PubMed up to April 2024 for studies published within the last five years on asthenopia, without language or design restrictions. Reference lists were also reviewed. The study quality was evaluated using the Newcastle-Ottawa Scale. A random-effects meta-analysis was conducted to calculate proportions, prevalence rates, odds ratios (ORs) and their 95% confidence intervals (CIs).ResultsOverall, 63 studies were included. The pooled prevalence of asthenopia detected via questionnaires or symptom report was 51% (95% CI = 50%, 52%). Subgroup analyses showed high prevalence among digital device users (90%) and computer workers (77%). During the COVID-19 pandemic, prevalence rose among adults (39%-45%), university students (36%-57%), and school-aged children (45%-64%). The most frequent ocular symptoms were eye tiredness (65%, 95% CI = 46%, 84%), eye strain (47%, 95% CI = 37%, 58%), and burning/irritation (43%, 95% CI = 35%, 51%). Musculoskeletal symptoms, including neck pain (45%, 95% CI = 28%, 62%) and shoulder pain (30%, 95% CI = 12%, 48%) were also prevalent. Neuropsychological symptoms included headache (50%, 95% CI = 41%, 59%) and difficulty concentrating (44%, 95% CI = 32%, 56%). Risk factors included short sleep duration (OR = 1.28; 95% CI = 1.04, 1.57), prior eye disease (OR = 2.59; 95% CI = 1.43, 4.69), prolonged screen time (OR = 1.15; 95% CI = 1.09, 1.21), and ambient conditions like air conditioning use (OR = 23.02; 95% CI = 4.94, 107.18). Protective measures included anti-glare filters (OR = 0.34; 95% CI = 0.19, 0.64), regular breaks (OR = 0.21; 95% CI = 0.09, 0.51), and computer use knowledge (OR = 0.20; 95% CI = 0.13, 0.30).ConclusionsAsthenopia is prevalent across diverse populations, characterised by a wide range of symptoms and influenced by modifiable risk factors. Our findings support a unified definition to improve clinical recognition and offer preliminary evidence to help shape future research on preventive strategies.RegistrationPROSPERO: CRD42024536841.