Evaluation of VDT-Induced Visual Fatigue by Automatic Detection of Blink Features

Computer Vision Syndrome: An Ophthalmic Pathology of the Modern Era

Digital device usage has increased significantly in last decade among all age groups, both for educational and recreational purposes. Computer vision syndrome (CVS), also known as digital eye strain (DES), represents a range of ocular, musculoskeletal, and behavioral conditions caused by prolonged use of devices with digital screens. This paper reviews the principal environmental, ocular, and musculoskeletal causes for this condition. Due to the high prevalence of DES and frequent usage of digital devices, it is important that eye care practitioners be able to provide advice and management options based on quality research evidence.

Effects of lying posture and task type on muscle fatigue, visual fatigue, and discomfort while using a smartphone on the bed

BACKGROUND

Neck-shoulder and arm musculoskeletal disorders in smartphone use have attracted increasing attention.

OBJECTIVE

This study aimed to examine the effect of different lying postures and task types by comparing the electrooculography (EOG) responses, perceived discomfort, and the activity of neck-shoulder and arm muscles while using a smartphone on the bed.

METHODS

Twenty participants were recruited to perform 30-min tasks (texting/ watching video) while holding the smartphone in three different lying postures (half-lying/lying/side-lying). Subjective discomfort, muscular activities including the abductor pollicis brevis (APB), upper trapezius (UT), and extensor carpi radialis (ECR), and EOG signals were simultaneously monitored.

RESULTS

The results showed that the perceived discomfort of measured body parts increased significantly over time in all postures. Watching video significantly increases muscle activities of APB and UT and decreases blink frequency and blink duration. Compared to lying or half-lying, the side-lying posture has the highest blink frequency, blink duration, and muscle activities in ECR and UT.

CONCLUSION

The findings of this study indicate that side-lying posture should be avoided while using a smartphone on the bed. It provides an understanding of the association between the postures of using smartphones on the bed and fatigue, which can help prevent muscle and visual fatigue in smartphone use.