Each physiotherapist welcomes a large number of patients working on the screen, and spontaneously associates oral complaints with the described working limitations. But how, without seeing the employee’s work and not knowing the social and professional context, can he advise his patient?
Over the past 20 years, the number of employees who are exposed to screen work and seats has increased significantly. A professional health record physician in tertiary secondary 3 major complaints: visual fatigue, diseases of the musculoskeletal system and stress. For the first two, we analyze the causes and ergonomic recommendations. Finally, we discuss the context and methods of physiotherapist intervention.
Eye exercises for office workers. Physiology and visual impairment, risk factors. Large epidemiological studies conducted over the past 10 years have not been able to demonstrate the existence or worsening of visual pathologies associated with screen work. The 3 most popular visual functions when working on the screen: adaptation (which supports the image on the retina by changing the curvature of the lens), adaptation (which regulates the amount of light entering the eye. Varying pupil diameter) and convergence (which supports binocular vision by converging the two axes of vision to the observed point).
These 3 functions have a common point of regulation of the external oculomotor muscles that control convergence, and their own (ciliary) muscles that control accommodation and adaptation, affecting the lens and iris. It is over fatigue of these muscles that cause visual fatigue, a recognized phenomenon that generates normative positions (see Clause 5). The visual comfort angle is 30 degrees below the horizontal axis. A long look above this angle reveals the upper surface of the eye, poorly moistened by the system.
Each physiotherapist welcomes a large number of patients working on the screen, and spontaneously associates oral complaints with the described working limitations.
But how, without seeing the employee’s work and not knowing the social and professional context, can he advise his patient? Prevention and health in the office: what should a physiotherapist know, what can he do? High temperature and low hygrometry, drafts and lens wear exacerbate this phenomenon and can lead to “dry eye syndrome”. Risk factors for visual fatigue are: age, general condition, certain medications (antipsychotics and biases) and visual defects not detected or corrected incorrectly. Environmental factors causing visual fatigue are display characteristics, natural and artificial lighting, hygrometry, installation of a post and organization of work.
Workplace ethics. Organization of work: The Regulation recommends limiting the time spent on the screen to 50 minutes in a row and six hours a day, alternating this work with “off-screen” tasks. Lighting: Visual comfort conditions: from 300 to 500 lux of lighting on the working surface with sufficient contrast, without dazzle and glare. The screen will be perpendicular to the windows (provide blinds to regulate natural light) and located between the lights. A lamp will be installed at the post (at the request of the employee). Artificial lighting should consist of recessed grating lamps (or, even better, indirect or mixed lighting) with “low brightness” lamps having an intermediate color temperature (from 3000 to 5000 K) and a good color rendering indicator (more than 80).
These recommendations imply an effect on the location of the screen, its adjustment in height and depth; these settings are not possible for a one-piece laptop, which must be reserved for nomadic work and converted to a connected central unit. to mobile devices when used in a “sitting” station. Adjustment of the screen and stations, compensating actions: it is desirable that the display has dark symbols on a light background. We will avoid associating colors poorly distinguished by dyschromatopsia (color blindness is best known), such as green, red, and blue. The employee will adjust the brightness and contrast of his screen during natural fluctuations in brightness.
He will adjust the scanning frequency of his screen above 80 Hz. The source documents will be placed at the department at the same height, distance and depth as the screen, or otherwise, tilt between the keyboard and the screen to limit placement efforts. The employee is invited to look away periodically to calm the muscles when accommodation is closer and to practice an exercise for eye relaxation, such as palming (the technique of eye relaxation).