The 20/20/20 rule: Practicing pattern and associations with asthenopic symptoms.

Purpose: The present work style and lifestyle have increased the digital device use. Therefore, an increase in digital eyestrain is to be expected. We undertook a survey during coronavirus disease 2019 (COVID-19) pandemic to investigate the practice of 20/20/20 rule and its association with digital device use and asthenopic symptoms. While this rule is commonly advised, little is known about its validity. Methods: An online survey form was disseminated through social media and emails. The questions for eye-related symptoms were similar to the convergence insufficiency symptom survey (CISS). Participants with age ≥5 years were included, with parents completing the survey for children (≤16 years). Results: A total of 432 participants (mean ± standard deviation [SD]: 26.06 ± 13.92 years) were enrolled, of which 125 responses were for children. The 20/20/20 rule was practiced only by 34% of the participants either regularly (n = 38) or occasionally (n = 109). Those who had complaints of burning sensation and headache tended to practice this rule. Among adult participants, more females (47%) practiced this rule when compared to males (23%). Also, adult females significantly (P = 0.04) had more symptoms score when compared to males. In children, no such gender difference was found. Conclusion: Only one-third of participants practice the 20/20/20 rule at least occasionally. More number of adult females being symptomatic and practicing in greater number could be due to higher prevalence of dry eye condition in females. While the symptom of burning sensation could be related to dry eye, that of headache could be related to refractive error or binocular vision dysfunctions.

Spasm of near reflex: a comprehensive management protocol and treatment outcomes.

PURPOSE: To report a consolidated management protocol for patients with spasm of near reflex (SNR), including classification of cases as mild, moderate, and severe based on treatment outcomes. METHODS: Patients with SNR treated at a single institution between August 2016 and November 2018 were included. Management of SNR included modified optical fogging, vision therapy, and pharmacological intervention (cyclopentolate eye drops and, if required, atropine eye drops). Outcome measures were visual acuity (20/25 or better) and refractive error (reduction of excessive myopia). RESULTS: Of 1,306 patients examined during the study period, 66 were diagnosed with SNR, yielding a prevalence of 5% among first-time patients visiting our binocular vision and orthoptics clinic. Of the 45 patients recruited for this study (mean age, 14 ± 5 years; 24 males), all three near-triad components were involved in 11 patients (24%), only the accommodation component in 32 (71%), and only the convergence component in 2 (4%). SNR was relieved in the first post-cyclopentolate refraction visit or with the modified optical fogging technique in 29 patients (66%; mild SNR) and with one-time usage of atropine eyedrops in 10 patients (22%; moderate SNR). In 6 patients (13%), atropine was continued long-term (severe SNR). Of 15 patients with long-term follow-up (1 year), 11 (73%) had persistent relief of SNR. CONCLUSIONS: In our study cohort, SNR with accommodation component was the most common and could be largely relaxed through a one-time use of cycloplegic eye drops and optical intervention. Only severe forms of SNR may require extended use of strong cycloplegics.

Factors affecting enhanced video quality preferences.

The development of video quality metrics requires methods for measuring perceived video quality. Most of these metrics are designed and tested using databases of images degraded by compression and scored using opinion ratings. We studied video quality preferences for enhanced images of normally-sighted participants using the method of paired comparisons with a thorough statistical analysis. Participants (n=40) made pair-wise comparisons of high definition video clips enhanced at four different levels using a commercially available enhancement device. Perceptual scales were computed with binary logistic regression to estimate preferences for each level and to provide statistical inference of the differences among levels and the impact of other variables. While moderate preference for enhanced videos was found, two unexpected effects were also uncovered: 1) participants could be broadly classified into two groups: a) those who preferred enhancement ("Sharp") and b) those who disliked enhancement ("Smooth") and 2) enhancement preferences depended on video content, particularly for human faces to be enhanced less. The results suggest that algorithms to evaluate image quality (at least for enhancement) may need to be adjusted or applied differentially based on video content and viewer preferences. The possible impact of similar effects on image quality of compressed video needs to be evaluated.