Computer vision symptoms in people with and without neck pain

Viewing distance, font size and symptoms of eyestrain in non-presbyopic and presbyopic smartphone users

PURPOSE

Smartphones are the most frequently used digital devices globally with ~6.80 billion users. Despite the ubiquitous use of smartphones, limited information is known on the preferred viewing distance and font size of smartphone users. This study investigated viewing distance, font size and symptoms of eyestrain in non-presbyopic and presbyopic smartphone users.

METHODS

In this quantitative research study, viewing distance and font size were measured in a group of non-presbyopes (n = 107) and presbyopes (n = 53), whilst participants viewed a text message and a web page on their own smartphone. Subjects also responded to a verbal questionnaire related to the characteristics of their smartphone and the computer vision syndrome questionnaire to assess symptoms of eyestrain. Data were analysed using descriptive and inferential statistics.

RESULTS

For the total sample, the mean viewing distance for a text message was 37.13 ± 8.82 cm (median 36.00 cm), and for a web page was 36.11 ± 7.98 cm (median 36.00 cm). Presbyopes had longer median viewing distances compared with non-presbyopes for a text message (41 cm vs. 34 cm, p < 0.001) and web page (40 cm vs. 34 cm, p < 0.001). The font size for non-presbyopes were <1.0 M whilst for presbyopes were >1.2 M. More than twice the percentage of non-presbyopes were classified with digital eyestrain (DES) compared with presbyopes.

CONCLUSIONS

Non-presbyopes used shorter viewing distances, smaller font sizes and were more predisposed to DES than presbyopes. The viewing distances adopted by presbyopes were similar to the conventional near-working distance of 40 cm. Eye care practitioners should consider viewing distances when assessing near-visual functions and prescribing a near refractive correction, particularly in non-presbyopes. There should be greater awareness of the importance of adopting appropriate viewing distances when using smartphones.

Prevalence and Interrelationships of Screen Time, Visual Disorders, and Neck Pain Among University Students: A Cross-Sectional Study at Majmaah University

BACKGROUND

Digital devices significantly contribute to vision-related problems. In addition, prolonged postural imbalance, owing to excessive use of digital devices, can lead to the tightening of head and neck muscles, resulting in neck pain, a common musculoskeletal discomfort that significantly affects individuals with poor vision. This study aimed to evaluate the prevalence and interrelationships of screen time, visual disorders, and neck pain among students at Majmaah University.

METHODS

A cross-sectional study was conducted at Majmaah University, Saudi Arabia, enrolling students aged 18 to 25 years. Exclusion criteria included neurological or musculoskeletal disorders. Demographic data and information on visual and neck pain symptoms were collected. The Neck Disability Index questionnaire was used to assess neck pain, and data were analyzed using SPSS version 24.0.

RESULTS

Among 263 participants, 53.6% were female. Nearsightedness (38.0%) and dry/itchy eyes (49.0%) were the most common visual disorders and symptoms, respectively. Visual disorders were prevalent in 62.0% of students, while neck pain was reported by 79.5%. Females and those studying for more than 5 h using electronic screens daily reported higher neck disability index scores. A significant association was found between >5 h of study duration [screen time] and neck disability (OR 3.703, 95% CI 1.500-9.144, p = 0.005).

CONCLUSION

The study highlights a relationship between visual problems and neck pain among university students, emphasizing the need for addressing vision-related issues to reduce neck discomfort. High screen time could substantially increase the odds of developing neck disability. However, authors warrant cautious interpretation in the light of following limitations: cross-sectional study, small sample size, lack of statistical power, and self-reported data.

Choroidal vascularity index in patients with computer vision syndrome combined with accommodative lead

BACKGROUND

This study aimed to investigate the choroidal vascularity index (CVI) in patients with computer vision syndrome (CVS) combined with accommodative lead.

METHODS

This retrospective case-control study enrolled patients diagnosed with CVS and accommodative lead at University-Town Hospital of Chongqing Medical University between July 2022 and May 2023. The control group included individuals without any ocular diseases. Ophthalmic assessments included basic visual acuity, refraction, ocular biometric parameters, and CVI.

RESULTS

A total of 85 participants were included in the study, with 45 in the CVS group and 40 in the control group. The central corneal thickness of CVS group was found to be significantly thinner compared to the control group in both the right eye (532.40±30.93 vs. 545.78±19.99 µm, P = 0.019) and left eye (533.96±29.57 vs. 547.56±20.39, P = 0.014). In comparison to the control group, the CVS group exhibited lower CVI in the superior (0.40±0.08 vs. 0.43±0.09, P = 0.001), temporal (0.40±0.08 vs. 0.44±0.10, P < 0.001), inferior (0.41±0.08 vs. 0.46±0.08, P < 0.001), and nasal (0.41±0.08 vs. 0.44±0.08, P = 0.001) quadrants. Similar differences were observed in all four quadrants within the 1-3 mm radius, and in the temporal (P = 0.004) and inferior (P = 0.002) quadrants within the 1-6 mm and 3-6 mm radii (all P < 0.05).

CONCLUSION

Compared to individuals without ocular issues, patients with CVS and accommodative lead were found to have thinner corneal central thickness and lower CVI.

Short-Term Effect of Spinal Manipulation on the Magnitude of Exophoria in Adults Who Are Asymptomatic: A Randomized Controlled Trial

OBJECTIVE

This study aimed to assess the immediate and short-term effects of cervical spinal manipulation (SM), compared with a placebo, on the magnitude of near and distance exophoria in adults with asymptomatic exophoria.

METHODS

In this single-blind, randomized controlled trial, individuals with a clinical diagnosis of horizontal exophoria confirmed with the prism alternating cover test (PACT) were allocated to a single intervention session using a high-velocity, low-amplitude cervical SM technique or a sham intervention (manual contact under the head). Outcomes were the magnitude of horizontal heterophoria, as a measure of binocular vision efficiency at near (40 cm) or distance (4 m) fixation, using the PACT. Evaluations were made at baseline, immediately after intervention, and at a 1-week follow-up.

RESULTS

From May to September 2021, 44 volunteers (23 women), with a mean age of 35 (SD = 9.5) years, were recruited and equally distributed into the study groups. All participants completed follow-up assessments, and no adverse events were reported. There was a significant time × group interaction for exophoria at near vision, but not at distance fixation. The SM group showed a significant decrease of near exophoria compared with the control group at the 1-week follow-up (mean difference = -1.09 prism diopters; 95% CI = -0.20 to -1.98 prism diopters).

CONCLUSION

The use of cervical SM therapy resulted in a significant reduction of the magnitude of horizontal exophoria at near vision (medium effect size), compared with the placebo, in young adults who are asymptomatic. However, these effects were not observed at distance fixation and should be considered cautiously due to the pre-post design with a single intervention session and the short-term follow-up.

IMPACT

The findings suggest short-term benefits of SM therapy can manage undiagnosed ocular convergence disorders, although changes were not clinically relevant.

Computer vision syndrome-related symptoms in presbyopic computer workers

PURPOSE

To evaluate the prevalence of computer vision syndrome (CVS)-related symptoms in a presbyopic population using the computer as the main work tool, as well as the relationship of CVS with the electronic device use habits and the ergonomic factors.

METHODS

A sample of 198 presbyopic participants (aged 45-65 years) who regularly work with a computer completed a customised questionnaire divided into: general demographics, optical correction commonly used and for work, habits of electronic devices use, ergonomic conditions during the working hours and CVS-related symptoms during work performance. A total of 10 CVS-related symptoms were questioned indicating the severity with which they occurred (0-4) and the median total symptom score (MTSS) was calculated as the sum of the symptoms.

RESULTS

The MTSS in this presbyopic population is 7 ± 5 symptoms. The most common symptoms reported by participants are dry eyes, tired eyes and difficulties in refocusing. MTSS is higher in women (p < 0.05), in laptop computer users (p < 0.05) and in teleworkers compared to office workers (p < 0.05). Regarding ergonomic conditions, MTSS is higher in participants who do not take breaks while working (p < 0.05), who have an inadequately lighting in the workspace (p < 0.05) and in the participants reporting neck (p < 0.01) or back pain (p < 0.001).

CONCLUSION

There is a relationship between CVS-related symptoms, the use of electronic devices and the ergonomic factors, which indicates the importance of adapting workplaces, especially for home-based teleworkers, and following basic visual ergonomics rules.

Effects of digital devices and online learning on computer vision syndrome in students during the COVID-19 era: an online questionnaire study

PURPOSE

Computer vision syndrome (CVS) describes a group of eye and vision-related problems that result from prolonged digital device use. This study aims to assess the prevalence and associated factors of CVS among students during the lockdown resulting from the COVID-19 pandemic.

METHODS

A cross-sectional, online, questionnaire-based study performed among high school students in Thailand.

RESULTS

A total of 2476 students, with mean age of 15.52±1.66 years, were included in this study. The mean number of hours of digital device use per day (10.53±2.99) increased during the COVID-19 pandemic compared with before its advent (6.13±2.8). The mean number of hours of online learning was 7.03±2.06 hours per day during the pandemic. CVS was found in 70.1% of students, and its severity correlated with both the number of hours of online learning and the total number of hours of digital device usage (p<0.001). Multiple logistic regression analysis revealed that the factors associated with CVS included age ≤15 years (adjusted OR (AOR)=2.17), overall digital device usage >6 hours per day (AOR=1.91), online learning >5 hours per day (AOR=4.99), multiple digital device usage (AOR=2.15), refractive errors (AOR=2.89), presence of back pain (AOR=2.06) and presence of neck pain (AOR=2.36).

CONCLUSIONS

The number of hours of digital device usage increased during lockdown. Over 70% of children had CVS, whose associated factors, including hours of digital device usage, hours of online learning, ergonomics and refractive errors, should be adjusted to decrease the risk of acquiring this condition. Online learning will remain, along with CVS, after this pandemic, and we hope our research will be taken into account in remodelling our education system accordingly.

Interventions for the management of computer vision syndrome: a systematic review and meta-analysis

TOPIC

To evaluate the efficacy and safety of interventions for treating eye strain related to computer use relative to placebo or no treatment.

CLINICAL RELEVANCE

Computer use is pervasive and often associated with eye strain, referred to as "computer vision syndrome" (CVS). Currently, there are no clinical guidelines to help practitioners provide evidence-based advice about CVS treatments, many of which are directly marketed to patients. This systematic review and meta-analysis will help inform best practice for eye care providers.

METHODS

Eligible randomized controlled trials (RCTs) were identified in Ovid MEDLINE, EMBASE, CENTRAL, and trial registries, searched from inception to November 23, 2021. Eligible studies were appraised for risk of bias, and synthesized. The certainty of the body of evidence was judged using GRADE. Standardized mean differences (SMD) were used when differently scaled measures were combined.

RESULTS

Forty-five RCTs, involving 4497 participants, were included. Multifocal lenses did not improve visual fatigue scores compared to single-vision lenses (three RCTs, SMD: 0.11; 95% confidence interval (CI) -0.14 to 0.37; p=0.38). Visual fatigue symptoms were not reduced by blue-blocking spectacles (three RCTs), with evidence judged to be of low certainty. Relative to placebo, oral berry extract supplementation for 4 to 12 weeks did not improve visual fatigue (seven RCTs, SMD: -0.27; 95%CI -0.70 to 0.16; p=0.22), and dry eye symptoms (four RCTs, SMD: -0.10; 95%CI -0.54 to 0.33; p=0.65). Likewise, berry extract supplementation had no effect on critical flicker-fusion frequency (CFF) or accommodative amplitude. Oral omega-3 fatty acid supplementation for 45 days to 3 months improved dry eye symptoms (two RCTs, mean difference, MD: -3.36 units out of 18; 95%CI -3.63 to -3.10; p<0.00001) relative to placebo. Oral carotenoid supplementation improved CFF (two RCTs, MD: 1.55 Hz; 95%CI 0.42 to 2.67; p=0.007) relative to placebo, although the clinical significance of this finding is unclear.

CONCLUSIONS

We found no high certainty evidence supporting the use of any of the therapies analyzed. There was low certainty evidence that oral omega-3 supplementation reduces dry eye symptoms in symptomatic computer users.

Is Altered Oculomotor Control during Smooth Pursuit Neck Torsion Test Related to Subjective Visual Complaints in Patients with Neck Pain Disorders?

Subjective visual complaints are commonly reported in patients with neck pain, but their relation to objectively measured oculomotor functions during smooth pursuit neck torsion tests (SPNTs) has not yet been investigated. The aim of the study was to analyse classification accuracy of visual symptom intensity and frequency based on SPNT results. Forty-three patients with neck pain were referred by orthopaedic outpatient clinics where they were required to fill out 16-item proformas of visual complaints. Infrared video-oculography was used to measure smooth pursuit eye movements during neutral and neck torsion positions. Parameters of gain and SPNT difference (SPNTdiff) were taken into the Naïve Bayes model as classifiers, while intensity and frequency of visual symptoms were taken as predicted class. Intensity and, to a lesser degree, frequency of visual symptoms previously associated with neck pain or focal vision disorders (computer vision syndrome) showed better classification accuracy using gain at neck torsion position, indicating cervical driven visual disturbances. Moreover, SPNTdiff presented with slightly lower classification accuracy as compared to gain at neck torsion position. Our study confirmed the relationship between cervical driven oculomotor deficits and some visual complaints (concentrating to read, words moving on page, blurred vision, difficulty judging distance, sore eyes, heavy eyes, red eyes, and eyes strain).

Different sit:stand time ratios within a 30-minute cycle change perceptions related to musculoskeletal disorders

Regular standing interruptions to sedentary work are recommended, but their dosage is understudied. To measure perception variations associated with different sit:stand ratios, 16 people used six ratios (30:0, 27:3, 24:6, 21:9, 18:12 and 15:15) within 30-min cycles in their normal office environment. At start and end of each workday, study participants recorded their perception of 11 factors on a 10-point scale. Musculoskeletal discomfort in 10 body regions was measured before and after exposure to sit-stand ratios. Overall preferred ratios were recorded. Sit:stand ratio affected all perceived factors, with impact varying. Standing at least 6 min improved results most overall; however, individual perceived factors were least impacted by any of 30:0, 27:3, 24:6 or 21:9. Preferred sit:stand ratios were 15:15, 18:12 and 21:9. Typically, least liked ratios involved briefest standing (30:0, 27:3, 24:6) although two participants least liked 15:15. Understanding these variations contributes to appropriate standing dosage recommendations.

The influence of neck torsion and sequence of cycles on intra-trial reliability of smooth pursuit eye movement test in patients with neck pain disorders

The sensory mismatch commonly observed in patients with neck pain disorders could alter intra-trial reliability in simple implicit smooth pursuit eye movement tasks. This could be more pronounced when neck is in torsioned position (SPNT). The aim of this study was to explore the effects of neck torsion, target movement velocity and amplitude on intra-trial reliability of smooth pursuit eye movements in patients with neck pain disorders and healthy individuals. SPNT test was evaluated in 32 chronic neck pain patients and 32 healthy controls. Ten cycles were performed using video-oculography at three different velocities (20° s^-1, 30° s^-1 and 40° s^-1) and at three different amplitudes (30°, 40° and 50°) of target movement. Intra-trial reliability and differences between average gain and SPNT difference from the second to fifth cycle and from the sixth to ninth cycle were assessed using ICC_3.1 and factorial analysis of variance, respectively. Intra-trial reliability for gain and SPNT difference at all target movement amplitudes and velocities proved to be good to excellent in both observed groups. Patients with neck pain disorders presented with a trend of inferior gain performance between the sixth and ninth cycle at 30° s^-1 of target movement as compared to healthy individuals which was only evident when neck was in torsioned position. Although intra-trial reliability of smooth pursuit neck torsion test is good to excellent, the effects of learning are not as pronounced in patients with neck pain disorders.

Computer Vision Syndrome in the Spanish Population during the COVID-19 Lockdown

SIGNIFICANCE

After 6 to 8 weeks of mandatory lockdown due to coronavirus disease 2019 (COVID-19) in Spain, the encouraged change in daily habits resulted in a significant increase in electronic device use. Computer vision syndrome-related symptoms were reported more often in participants who used electronic device for more time and spent less time outdoors.

PURPOSE

The main purpose of this study was to evaluate computer vision syndrome-related eye symptoms due to the use of electronic devices during COVID-19 lockdown decreed in Spain in 2020.

METHODS

After 6 to 8 weeks of strict lockdown, a total of 730 participants (18 to 73 years old) filled in a customized questionnaire divided into three sections: (1) general demographics, (2) usage habits of electronic devices during this period, and (3) computer vision syndrome-related ocular and visual symptoms associated with their use and with ergonomic practices.

RESULTS

The daily duration of use of electronic devices increased an average of 3.1 ± 2.2 h/d during the lockdown, with computer use increasing the most. The main symptoms reported by the participants were headache (36.7%), dry eye (31.1%), irritation (24.1%), blurred vision (21.2%), and ocular pain (14.9%). There was a significant relationship between computer vision syndrome-related symptoms and age (greater in participants between 18 and 30 years old than in those older than 45 years, P < .001), primary activity (greater in studying from home and remote working, P < .001), and extended periods of electronic device use (greater when used more than 10 h/d, P = .05). Symptoms were also associated with time spent outdoors (greater in participants with <1 h/d, P = .02).

CONCLUSIONS

The lockdown due to COVID-19 showed an increase in the electronic device use. Participants who spent more time with electronic devices and less time outdoors reported more computer vision syndrome-related eye symptoms.

Accommodative and binocular disorders in preteens with computer vision syndrome: a cross-sectional study

To assess computer vision syndrome (CVS) in a preteen population through an adult-validated CVS questionnaire and to evaluate how digital devices affect accommodative and binocular vision, we enrolled 309 preteens in this cross-sectional study. An adult-validated CVS questionnaire adapted to preteens was used for all subjects. Visual acuity testing, unilateral and alternate cover tests, and tests for accommodative and vergence responses were performed for all preteens. The mean age was 10.75 ± 0.67 (10-12) years. Subjects were divided into two groups: the mild CVS group with a mean CVS score ≤2 and the severe CVS group with a mean CVS score >2. Between the mild and severe CVS groups, statistically significant differences were found in near point of convergence break and recovery (P = 0.03 and P = 0.02, respectively) and distance negative fusional vergence break and recovery (P = 0.02 and P < 0.01, respectively). More children with severe CVS developed vergence disorders than those with mild CVS. Optometric clinical screening assessments could reduce ocular symptomatology and prevent long-term effects. However, poor optometric findings might have occurred first, and the poor convergence skills resulted in the symptoms reported while using devices.

Impact of an educational intervention using the 20/20/20 rule on Computer Vision Syndrome

Background: Global estimates suggest that nearly 60 million people suffer from Computer Vision Syndrome (CVS).Aim: The goal of this research was to evaluate the effectiveness of an educational intervention using the 20/20/20 rule to reduce CVS symptoms.Setting: The study was conducted in the Qassim University eye clinic.Methods: An experiential intervention study was conducted amongst 40 patients with CVS, with their age ranging from 21 to 38 years. The sample was divided into two groups: (1) intervention patients (n = 20), who were given a structured advice booklet about how to reduce CVS symptoms using the 20/20/20 rule, and (2) control (n = 20) with CVS, who were given advice to simply drink more water. Both groups completed two questionnaires, namely, the CVS-Q and Dry Eye Questionnaire-5 (DEQ-5). Dry eye clinical tests were performed. The same procedures were repeated after 20 days to compare the outcomes before and after intervention.Results: The study findings revealed that patients complaining from dry eye symptoms showed significant changes after the educational intervention (pre-intervention: 9.05 ± 4.32; post-intervention: 7.10 ± 3.61) (p = 0.04). The symptoms of CVS were slightly reduced after educational intervention, from 9.00 ± 3.03 to 8.35 ± 1.89 (p = 0.38). However, TBUT showed a significant increase after the educational intervention (pre-intervention: 6.20 ± 2.02 s; post-intervention: 8.55 ± 2.84 s) (p = 0.005).Conclusion: The educational intervention of the 20/20/20 rule induces significant changes in dry eye symptoms and tear film and some limited changes for ocular surface integrity.