[Digital eye strain. Functional symptoms and binocular balance analysis in intensive digital users]. / Stress oculaire induit par les écrans. Analyses des symptômes fonctionnels et de l'équilibre binoculaire chez des utilisateurs intensifs.

INTRODUCTION: In almost 50 % of cases, acute or chronic screen exposure is accompanied by symptoms of dry eye or binocular imbalance, known as digital eye strain. This phenomenon is described relatively little in the literature. The goal of this study is to determinate the effects of screen exposure on subjective comfort and binocular balance. PATIENTS AND METHODS: This is a cross-sectional, prospective, monocentric pilot study conducted from August to October 2019. The first part of the study focused on disturbances induced by short-term screen exposure (comparison between morning and evening examinations) between a control group (less than 5hours a day) and an exposed group (more than 5hours a day). The second part investigates the consequences of chronic exposure (screen exposure greater than 5hours a day, 5 days a week for one year) excluding pre-presbyopic and presbyopic patients (over 35 years of age). The study parameters consisted of an ocular discomfort questionnaire and binocular function tests (refraction, phoria, near point of accommodation and convergence, fusional vergence (FV), and binocular amplitude facility (BAF)). RESULTS: Short exposure : 52 participants were included. No significant difference was found between the control group (n=24, mean exposure=2.6 hr) and the exposed group (n=28, mean exposure=6.1 hr) for any of the objective parameters. The ocular discomfort score was highest in the exposed group for the following parameters: near (p=0.04) and intermediate (p=0.02) blurred vision and light sensitivity (p=0.04). Chronic exposure: 35 participants were included. The exposed group (n=12, mean exposure=6.7 hr) showed a decrease in FV (p=0.045) and BAF (p=0.038) compared to the control group (n=23, mean exposure=2.1 hr). DISCUSSION: Binocular balance is disturbed by intensive and chronic use of screens. Special attention must therefore be paid to these patients.

Vestibular asthenopia.

Vestibular asthenopia, analogous to visual asthenopia, is a sensory (or sensory-motor) discomfort consisting of a set of subjective symptoms, the expression of which is essentially visual and whose origin is a transient vestibular incident. It can be considered the result of a sudden global central disorder, such as a "computer glitch," following a chain of events in response to an initial vestibular disease, even minor and devoid of clinical signs. This disorder results in inadequate processing and imperfect integration of afferent visual and vestibular input, leading to ocular fatigue, pain associated with eye movement, and sensitivity to retinal slip.

[Digital eye strain. Symptoms, prevalence, pathophysiology, and management]. / Perturbations oculaires secondaires à l'utilisation de supports numériques. Symptômes, prévalence, physiopathologie et prise en charge.

The digital revolution, which has been underway since the 1980's, is disrupting our daily routines with an exponential increase in the use of screens, which has not been without consequence to our visual system. Digital eye strain (DES), or computer vision syndrome (CVS), includes all the visual symptoms secondary to the use of digital devices. DES is present in at least 50% of regular users of digital media and is defined by blurred vision, difficulty focusing, ocular irritation or burning, dry eye, visual fatigue, headaches and increased sensitivity to light. Exposure time, age, female gender, and work environment are the main factors increasing its prevalence. Its pathophysiology, still poorly understood, is felt to be multifactorial and includes disturbances in the accommodative-convergence balance and changes in the ocular surface. Regarding accommodation and convergence, the studies are mostly old and their results heterogeneous. Conversely, many studies have shown an increase in the prevalence of dry eye in screen users. Although the retinal toxicity of blue light has been proven in in vitro models, the low level of evidence in the available studies does not allow it to be clearly correlated with the symptoms of DES. The objective of this review is to condense the knowledge available in the literature on the symptoms, prevalence, pathophysiology and management of DES.