Suboptimal visual ergonomics (i.e., the interaction between our vision, the light, the visual object, and the influence of other factors which impairs visibility) in work environment such as glare can cause headache in combination with eyestrain, visual ability, and musculoskeletal strain. Symptoms constituted to the syndrome of eyestrain has been well described among computer workers (see for example Han et al., 2013; Portello et al., 2012; Bhanderi et al., 2008; Mocci et al., 2001; Sanchez-Roman et al., 1996). However, research has not focused on investigating the presence of headaches associated with eye-related and musculoskeletal disorders among employees and visual related environmental factors.

The purpose of presented research was to study the presence of headaches in combination with visual ability, eye- and musculoskeletal strain, and work ability in connection with visually demanding work. Trained assessors recruited study participants primarily from their regular clients in the OHS field. Evaluators were instructed to recruit participants with a variety of characteristics to ensure highly variable data, such as different work tasks, age, and gender. The participants mean age was 48.3 years (±10.3); 66% were women.

A visual ergonomics risk assessment method (VERAM, Heiden et al. 2019; Zetterberg et al. 2017) was used to compile the participated workers subjective grading of headache, eye- and musculoskeletal strain using a questionnaire (n=430). At the same time, an evaluation of the visual environment was carried out, which established if there was a risk of glare associated with the implementation of work task (e.g., computer work and other related work such as industry, healthcare, and shipping industry). The frequency of headaches was divided into three categories; (1) no headache, (2) headache occasionally, and (3) headache a few times per week/almost every day. 

The measurements regarding evaluation of the visual environment used a photometer, an instrument which was available and that the assessors could use, usually a Hagner ScreenMaster or Hagner S1 / S2 / S3.

About 65% of the workers reported headaches occasionally, a few times/week or almost every day. Among the workers with headaches reported about 29% of them that they experienced the headaches a few times/week or almost every day.

Out of the workers with headaches reported 37% a severity of the headaches of more than 3 (on a scale of 1-10) and 5 % reported a severity of more than 6. About 40% of the workers also stated that the headaches affected their working ability. The headaches were mainly located around the eyes, forehead, or temples (70%) and came in the afternoon (69%). About 75% of the workers also reported that the headache disappeared or were reduced when they were off work for one night or over the weekend. The data collection showed that visual- related symptoms increased the higher the estimated headaches was.

The musculoskeletal strain increased when the headache increased. When workers reported a high frequency of headaches 95% of them reported neck strain, 86% shoulder strain, 73% upper back strain, and 61% were reported arm strain.

Moreover, only 8.2% of the workers rated their visual ability as bad or very bad, but at the same time, about 60% reported dim vision, 14% diplopia, and 59% problems changing focus at some time.

Dividing the data into workers with experienced or unexperienced headaches this study has shown that there was a significant presence of headaches in combination with visual related symptoms regarding experienced photophobia (p=0.011), eye pain (p=0.015), diplopia (p=0.029), and arm strain (p=0.006). Further, the statistical analysis showed that there was a tendency of combination regarding headaches and visual ability (p=0.070).

Dividing the data into workers with experienced or unexperienced headaches, our study showed that the frequency of headache increased due to high luminance levels within the visual field (p=0.044).

This study concludes presence of headaches in combination with eye- and musculoskeletal strain performing work task such as computer work. Further, the presence of headaches is due to visual ability induced by high luminance levels within the visual field.