Introduction

Vision, being the essential human sense, needs ideal lighting to ensure visual comfort in both living and working spaces. The right quality and quantity of lighting in workplaces impacts information reception and processing, visual fatigue, work productivity, emotional variations, and an individual’s mood in professional settings1,2. Health care systems are recognized as among the most extensive and costly sectors of employment. In numerous developing nations, over 5% of the Gross Domestic Product (GDP) is dedicated to the healthcare sector, with hospitals receiving more than 20% of the total health-related resources. Conversely, the obligation to deliver medical services and ensure comprehensive patient care falls primarily on the various departments within hospitals3,4.

In recent years, there has been a growing interest among researchers in examining how the lighting conditions experienced by hospital staff correlate with various aspects of workforce health, service quality, employee satisfaction, and job performance. Consequently, numerous studies within the domains of occupational health and ergonomics have explored lighting conditions and visual comfort as significant environmental factors that influence the occupational effectiveness of healthcare workers5,6,7. This kind of Hospital workplaces heavily depend on an appropriate lighting system. The quality of services rendered in hospitals is significantly influenced by the employees’ perception of visual comfort, which is inherently linked to the nature and critical importance of the healthcare services provided8,9. Since occupational risk factors such as musculoskeletal disorders, workload and work-related stress are affected by workplace lighting, paying attention to optimal lighting (in terms of quantity and quality) to provide visual comfort has received a lot of attention. Ensuring optimal lighting conditions can enhance workplace productivity, improve precision by minimizing errors, alleviate physical stressors, and decrease both mental fatigue and the incidence of musculoskeletal disorders within hospital environments7,10. The establishment of visual comfort through light and color is characterized by personal interpretations and subjective visual experiences that are influenced by a range of factors, including physical, physiological, cultural, and social responses. These elements can significantly impact an individual’s five senses, shaping their overall perception and experience of their environment11.

Visual discomfort has been identified as a significant factor contributing to medication errors, diminished employee performance, and a rise in injuries within hospital settings10,12,13. Creating visual comfort plays a crucial role in regulating the biological clock and enhancing both the physiological and psychological functions of the body’s neuroendocrine glands. Consequently, it is essential to comprehend the lighting requirements specific to various work environments, particularly with regard to achieving optimal visual comfort11,14,15.

The establishment of visual comfort is influenced by a multitude of elements, including architectural characteristics, spatial arrangement, interior design, the lighting system and its inherent properties, as well as personal factors16,17,18,19. Consequently, a comprehensive analysis of visual comfort necessitates an interdisciplinary approach that draws from various scientific fields20,21,22. Research focused on tools for evaluating visual comfort has predominantly emphasized physiological aspects within non-occupational settings, with comparatively limited investigations addressing the visual comfort associated with lighting systems in workplace environments18,23,24.

While numerous studies pertaining to hospital lighting have predominantly concentrated on its effects, there remains a significant deficiency in research specifically aimed at visual comfort. Consequently, only a limited quantity of studies has examined the influence of lighting conditions on visual comfort within hospital environments. This inadequacy underscores the necessity for a more thorough understanding of optimal lighting systems and the critical factors that affect visual comfort in these contexts. Hence, this study aspires to identify the barriers and facilitators of visual comfort as perceived by hospital personnel, employing qualitative research methodologies to obtain insights into this crucial aspect of healthcare design.

Methods

This study, using a qualitative research design and conventional content analysis (inductive approach), was to address the following question:

  • What is WVC from the perspective of hospital staff?

As content analysis had a valuable position in qualitative research, wherein transcribed data could be analyzed to extract their main themes, it was recruited in the present study to find certain words and concepts, and then reduce and categorize them25. Of note, the use of prearranged categories was avoided in its conventional approach, and they were merely allowed to emerge from the data26.

The data were acquired from the study participants, selected via purposive sampling. All these hospital staff members were engaged in specialized activities in different hospital wards, and showed their willingness to share their experiences with the researchers. The study was conducted in 2023 at two general hospitals, affiliated to Semnan University of Medical Sciences (SUMS), Semnan, Iran. The data collection method was semi-structured in-depth interviews based on open-ended questions. The interviews were completed individually in a quiet setting and at a suitable time when the participants felt at ease (approximately 60 min). The interviews were conducted with 16 participants, and two more for further certainty.

In this qualitative study, before beginning the main data collection phase, two interviews were conducted as a pilot phase to practice interviewing skills, refine the interview guide, and evaluate the recording quality of the interviews. In this scenario, the data from the pilot phase might not be included in the final analysis because the interview was not yet in its final, refined state. However, this doesn’t mean the main data is being discarded; it signifies a step that occurs before the actual, analyzable data collection begins.

Also, due to data saturation, interviews were conducted up to participant number 16, but for greater certainty, interviews were also conducted with two other participants to ensure that the data had reached complete saturation.

Upon obtaining their consent, the researchers took their home addresses and phone numbers at the end of the interviews to confirm their statements or conduct complementary interviews. Considering the research question, the interviews were initially started with some general questions, such as, How long have you been working in this hospital ward? How many years of working experience do you have? How many wards have you been working in? and How do you think the lighting of the working environment affects your job performance?

Upon receiving their answers to the abovementioned questions, the in-depth, exploratory ones were raised, e.g., Can you explain more? What does it mean? and Why?

Given that the instantaneous recording of the data was a prerequisite in qualitative research, the interviews were recorded with the consent of the participants, and then immediately transcribed verbatim. The participants included 18 hospital staff members working in different hospital wards for at least one year. They were interviewed individually one or two times. One more inclusion criterion was holding an Associate’s degree in terms of educational attainment. The interviews were also conducted in their workplace, and each interview lasted 50 min on average or 1 h at longest. All interviews were fulfilled by one interviewer.

The data collection and analysis were performed simultaneously in this study. All interviews were thus recorded, transcribed, and reviewed a couple dozen times for immersion purposes. Afterward, primary codes were extracted. Then, the identical ones were selected to create the potential subcategories under one category, and the corresponding categories were subsequently exploited to develop the main themes. Of note, each theme was reviewed and matched with the participants’ statements. At the last step, the main themes were modified and defined. Throughout the data collection and analysis process, all reflections and mental sparks related to the data that came to the researcher’s mind were written down and used for the subsequent interviews. Ethical considerations, such as obtaining informed consent, ensuring the confidentiality of the interviews, and giving the right to the participants to withdraw from the interviews and the research process at any time, were also observed.

To practice the data analysis, first, the interviews were read several times to immerse in the data, and then analyzed using constant comparison methods and conventional content analysis based on the step-by-step method described by Kuwal (1996)26. In this way, the data were categorized in the form of semantically conceptual units, such as codes, subcategories, and categories25.

To confirm the validity and rigor of this study, the researchers were completely involved in data extraction. The texts and interviews and the list of the categories were also reviewed by the research team with sufficient experience in qualitative research, and four criteria of credibility, dependability, confirmability and Transferability were further respected. For this purpose, continuous observations, long-term involvement in the study setting, allocation of enough time to check details, and verifiability of the findings by the research team and participants were exercised. For this purpose, continuous observations, long-term involvement in the study setting, allocation of enough time to check details, and verifiability of the findings by the research team and participants were exercised27.

As for Transferability, it should be said that transferability is an active act on the part of the reader. By providing a rich and detailed description, the researcher turns the reader into a judge who decides whether the study findings are relevant and applicable to his or her context and circumstances. Therefore, the presence of transferability in an article means that there is sufficient detail to make this judgment. In this qualitative study, Transferability is not presented as a separate section (like the statistical analysis section in quantitative studies). Instead, researchers address this concept by providing a “thick description” throughout the paper, especially in the methodology and findings sections. The primary responsibility is for the researcher to provide the reader with sufficient data to enable them to judge the Transferability of the findings to their own context. this study, to ensure the validity of the mixed-method research and the credibility of the findings from the perspectives of the researcher, participants, and potential readers, test-retest reliability and inter-coder reliability were assessed, following the criteria suggested by Creswell (2007). For test-retest reliability, three interviews were purposively selected from the dataset and each was coded twice, with a 15-day interval. The resulting reliability coefficient exceeded 0.60, indicating an acceptable level of stability in coding over time. To establish inter-coder reliability, the intra-subjective agreement method was employed. An academic expert with substantial experience in qualitative interview analysis was invited to serve as a secondary coder. The inter-coder agreement reached approximately 80%, which, being above the generally accepted threshold of 0.60, confirms that the coding process was sufficiently reliable28.

Ethical considerations

All methods were performed following Iranian ethical guidelines and regulations. This study received ethical approval from the Research and Ethics Committee, Mazandaran University of Medical Science (IR.MAZUMS.REC.1401.199). Before conducting the interviews, informed consent was obtained, which encompassed all necessary assurances regarding confidentiality, anonymity, and a commitment to prevent retaliation. No incentives were provided to the participants. During the interviews, we anticipated any anxiety participants might experience when discussing potential emotional traumas as thoroughly as possible. Plans were established to ensure the safety of participants in case of any special circumstances. Each participant provided oral consent in addition to written consent. Participants were informed that they could withdraw from the study at any time. All transcripts were stored on password-protected computers, accessible only to the researchers. During the data analysis process, the real names of each participant were concealed.

Results

The study results, considering the demographic characteristics (Table 1) of the participants (56% of participants were male and and the average work experience of participants was 13.5 ± 4.2 years) and the in-depth analysis of the interviews, led to three themes, viz., (i) no consideration of efficiency and structural design standards, (ii) eye damage caused by exposure to unnatural light range and a heavy workload, and (iii) a sense of comfort arising from attractive and standard design of hospital wards (Table 2), under eight categories and 23 sub-categories. Table 3 also lists an example of the coding process.

Table 1 Demographic characteristics of the participants.
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Table 2 Themes, categories, and subcategories developed in the present study.
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Table 3 An example of interview coding process.
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Upon reading the interviews and unravelling the semantically conceptual units as codes, 763 primary codes were obtained, and then divided into three main themes following the continuous comparison and analysis of the data, i.e., (i) no consideration of efficiency and structural design standards, (ii) eye damage caused by exposure to unnatural light range and a heavy workload, and (iii) a sense of comfort arising from attractive and standard design of hospital wards, under eight categories and 23 sub-categories, as given in Table 2.

In terms of WVC among the hospital staff members according to the existing infrastructure, the managerial and professional ones were not available in the given teaching hospitals. If appropriate infrastructure was provided, it could bring WVC. Of note, satisfaction was at higher levels in the hospital wards with the acceptable infrastructure, thereby leading to WVC in the hospital staff.

Main themes

Lack of managerial attention to the work environment and standard lighting system design

The first theme, namely, no consideration of efficiency and structural design standards, consisted of three categories of (i) thermal stress and disturbing reflections of surfaces like ceilings, floor, and walls, (ii) reduced efficiency due to poor organizational management, and (iii) no attention to environmental lighting.

Thermal stress and disturbing reflections of surfaces like ceilings, floor, and walls

The first category, i.e., thermal stress and disturbing reflections of surfaces like ceilings, floor, and walls, contained three subcategories of (i) consequences of light intensity affected by high and short ceilings, (ii) light reflections caused by unprincipled floor and wall designs, and (iii) thermal stress.

  • Consequences of Light Intensity Affected by High and Short Ceilings: With regard to the high and short ceilings of the hospital wards, there were different viewpoints. In this context, Participant P6 stated that: “I feel insecure once I see the ceiling is too high.” However, Participant P18 believed that: “High ceilings can give you a big sense of comfort. You always feel like you have much space.” Participant P.12 also asserted that: “I never suggest anywhere with ceilings below two meters high because you always feel like you are suffocating.” The other consequence was making some changes in lighting intensity. In this line, the number of light bulbs needed to be added, or their types had to be changed if the ceilings were high in order to provide enough light in the working environment. In this regard, Participant P.12, having 15 years of working experience, uttered that: “If ceilings are too high, the lighting you always expect will be no longer met. In this case, you should either buy light bulbs with different types and degrees of intensity, or change their number and types.”

  • Light Reflections Caused by Unprincipled Floor and Wall Designs: On the subject of light reflections caused by unprincipled floor and wall designs, the study participants did not like walls and floor with too bright colors, so the light reflections would not strain their eyes. In this line, Participant P.11 expressed that: “Reflections are irritating. The floor should not be too bright because it always leads to light reflections. There should be something moderate. It should not be too bright or too opaque.” But, another participant (P.7) maintained that: “The walls and ceilings are thankfully visible, but the color of the floor should be lighter because when something falls down, you can easily find it. It also helps you see the contamination.”

  • Thermal Stress: One of the main barriers that could give rise to no WVC was the heat caused by the use of the least energy-efficient light bulbs, the number of light bulbs installed in the hospital wards, and the heat coming from the surrounding environment, which could cause medical glasses to steam up during the related procedures. This could even be the occasion of irritation and error occurrence. In this vein, Participant P3, with 11 years of working experience, said that: “The light bulbs used in this ward produce much heat. This makes you sweat while working. The heating is sometimes so high that the hospital staff members feel bad.”

Reduced efficiency due to poor organizational management

Among the categories obtained in this study was reduced efficiency due to poor organizational management, which consisted of two subcategories, viz., (i) no motivation among hospital staff due to poor organizational management and (ii) low efficiency following poor management.

  • No Motivation among Hospital staff due to Poor Organizational Management: A poor management system in the hospital ward could directly affect the levels of motivation in the hospital staff, namely, making them demotivated after observing things such as not paying attention to environmental lighting. For example, Participant P12 reiterated that: “There were many promises that were not fulfilled. As an example, they said they would replace old light bulbs with new ones, but they have not still done so. It makes you feel unmotivated to be in this working environment.”

  • Low Efficiency following Poor Management: No satisfaction with old lighting equipment and no attention to the lighting system were among the factors brought up by Participant P9, having six years of working experience, which could drive down efficiency in the hospital staff, as: “The doctor’s examination room does not deserve their dignity. All these moonlight light bulbs must be changed. Here, you are reminded of a prison cell when you look at the ceiling. I think the lighting must be changed. In my opinion, the most energy-efficient light bulbs that are trendy must be used. Let’s look at the moonlight light bulbs, they are all shaded.”

No attention to environmental lighting

One of the categories established in this study was no attention to environmental lighting, with two subcategories of (i) lack of attention to lighting and (ii) failure to replace old equipment with standard and high-quality ones.

  • Lack of Attention to Lighting: Regarding the lack of attention to lighting, Participant P5, with four years of working experience in the occupational health unit, acknowledged that: “I have always gone and measured the lighting system of the hospital. Someone was telling me if the lighting could be measured with surprise! Was it important? No one like a nurse or a doctor who has studied about professional health knows that lighting is vital for the delivery of healthcare services.”

  • Failure to Replace Old Equipment with Standard and High-Quality Ones: Among the subcategories mentioned in this line by the study participants was failure to replace old equipment with standard and high-quality ones. On the topic of failure to replace light bulbs on time, Participant P12, having 15 years of working experience, said that: “The hospital staff declared that a light bulb was burnt out. No matter how much we called the facilities staff, but they did not come. After a long time, they came to change it. Of course, this could have many reasons, but the philosophical reason was that the given ward where the staff members were working did not seem reasonable to have proper lighting by the technical unit. The presence of one or two or more burnt-out light bulbs was not very important to them.”

Visual annoyance caused by unnatural inappropriate lighting system combined with a high workload

The second theme achieved according to the interviews with the participants was eye damage caused by unnatural light range and a heavy workload, comprised of three categories of (i) visual damage caused by fluctuating light intensity, (ii) visual fatigue and drowsiness following long working shifts, and (iii) error occurrence due to unsafe and crowded working environment”.

Visual damage caused by fluctuating light intensity

The fluctuating degree of light intensity in the hospital wards was among the major factors that could damage the visual sense in the hospital staff. This category involved three subcategories of (i) decreased accuracy and concentration due to low or high light intensity, (ii) eye damage caused by low light, and (iii) reduction of light intensity owing to minimal cleaning of light bulbs.

  • Decreased Accuracy and Concentration due to Low or High Light Intensity: The study findings revealed that accuracy and concentration could be decreased in the working environment with high or low degrees of light intensity, and then affect the physiological state of the hospital staff. In this regard, a 44-year-old nurse (Participant P8) asserted that: “Too much light directly leads to eye fatigue. It is like walking without sunglasses on a snowy day. Now imagine working in the same position and recording 30 files. It seems to be very bothersome. You get a headache. You even get sick and tired.”

  • Eye Damage Caused by Low Light: Among the subcategories raised by the study participants was eye damage caused by low light. One of the participants, having 13 years of working experience, accordingly said that: “If the light is below standard, you feel your eyes are constantly under pressure. You have to narrow and widen one’s eyes. I think the best standard situation is when the same light is provided.”

  • Reduction of Light Intensity owing to Minimal Cleaning of Light Bulbs: About the cleaning of the light bulbs, a female participant (P5) working in the occupational health unit affirmed that: “The decrease in brightness can be induced by the lack of complete cleaning of the light bulbs and their frames. I saw that the light bulb in front of the room was very low. They had asked to change it, but I think it was ok. I saw that the frame was very dirty. I removed the frame and gave it to be serviced, washed, dried, and put in its place. It was as bright as the first day, that is, the frame just needed to be cleaned.”

Visual fatigue and drowsiness following long working shifts

Another category addressed in this study after the final coding of the interviews was visual fatigue and drowsiness following long working shifts, holding two subcategories of (i) SRSDs arising from working shifts and environmental conditions and (ii) fatigue caused by long working shifts and a heavy workload.

  • Circadian rhythm sleep disorders (SRSDs) Arising from Working Shifts and Environmental Conditions: For various reasons, the hospital staff had to accept long working shifts per month, which could cause a change in their circadian cycle and lead to visual fatigue. On the subject of visual fatigue and drowsiness following long working shifts, a participant (P9) maintained that: “Suppose you have had all night, morning, and evening working shifts, you normally get tired, your sleep and nutrition are often messed up. Once you are serving in the emergency room, at midnight, at 2 or 3 a.m. later, you fall fast asleep, but your eyes are bothered, and the work is like you also have eye strain. Too much light hurts the eyes. It is a demanding situation.”

  • Fatigue Caused by Long Working Shifts and a Heavy Workload: Among other subcategories extracted in this study was fatigue affected by long working shifts and a heavy workload, which was expressed by Participant P17, having six years of working experience: “I am talking about the outlandish pressure of the working conditions. You see, the hospital staff members are low, and the patients are sick, but they have much work and tight schedules. I must not have seven tight working shifts in a month. This is a tragedy. Now, I have leg pain and suffer from backache. I have eye strain, and I am laid up with a headache.”

Error occurrence due to unsafe and crowded working environment

The study participants believed that errors could occur in unsafe and crowded working environments. In relation to the codes elicited from the interviews, this category contained two subcategories, viz., (i) an increase in errors attributable to a heavy workload and (ii) errors caused by unsafe lighting of working environment.

  • An Increase in Errors Attributable to a Heavy Workload: The study participants pointed to the problem that a heavy workload could bring about, that is, an increase in human errors. In this respect, one of the participants (P8) with 22 years of working experience asserted that: “Much work makes you wear down sooner. As well, fatigue and the state of having a great deal to do make your accuracy much lower. You even do not have time to drink a cup of tea, you do not have enough time to do so and so. It turns out that the results of your activities render null and void, and your mistakes progressively increase.”

  • Errors Caused by Unsafe Lighting of Working Environment: The unsafe working environment from various perspectives, including ambient lighting, especially in the treatment room and at the bedside, could cause errors and augment the number of mistakes. In this regard, Participant P4 said that: “The light intensity is not good, thereby making it difficult to see the veins. If it is too bright or too dark, it can have an effect on the visual sense and even cause harm to the patient.”

A sense of comfort arising from attractive and standard design of hospital wards

The last theme found based on the interviews was a sense of comfort arising from attractive and standard design of hospital wards, which was made up of two categories, i.e., (i) comfort induced by suitable architecture with soft and bright colors and (ii) satisfaction with combined or portable lighting according to work and time.

Comfort induced by suitable architecture with soft and bright colors

The study findings demonstrated that the given category included five subcategories of (i) need to beautify the working environment to maintain peace, (ii) a good feeling caused by the use of soft and cold colors, (iii) need for windows in the right position, (iv) preference to use light bulbs with white light, and (v) discouragement following the use of non-harmonious colors.

  • Need to Beautify the Working Environment to Maintain Peace: The first subcategory was the need to beautify the working environment to maintain peace. In this regard, the study participants believed that the beautification of the environment and the use of the appropriate colors and designs in the emergency room or other hospital wards had induced a sense of peace and made them feel better. For example, a participant (P6) with 22 years of working experience expressed that: “The color of the walls and the design in general are of utmost important. Here, the pediatric emergency room was recently built, so the ceiling light bulbs are really beautiful. I think the ceiling with lighting and beautiful shapes distracts children when you try to find their veins. This makes it easier for them to endure the emergency room and the hospital altogether. A relative calmness is thus induced. A child placed in a space that seems like their own accordingly makes them accept it more easily.” In this regard, Participant P8 talked about the use of panels with different designs as follows: “In my opinion, signs that invite people to feel relaxed or beautiful landscapes are more popular now. It would be good if they were installed everywhere in the hospital wards.” Participant P9 also added that: “The hospital environment is not very interesting if it is in cold colors, but when designs and sceneries are on the walls and ceilings, it has a positive effect on their mood. There are many times when patients lose their mood and have no motivation, but such activities are a kind of motivation and raise hope.”

  • A Good Feeling Caused by the Use of Soft and Cold Colors: The second subcategory was a good feeling caused by the use of soft and cold colors. In this regard, the participants believed that strong colors could make the hospital staff anxious and the soft ones could give them a good feeling. For example, Participant P18 said that: “In general, the places where there are the walls, floor, beds, bedding, and curtains make you get annoyed if strong colors are used. There should be no warm and neutral colors. We need purple and gray. The combined colors and the set should seem beautiful. I can easily handle the colors that are softer and work with those colors. Soft colors make everyone feel better than the dark and harsh ones that make you nervous.”

  • Need for Windows in the Right Position: The third subcategory was need for windows in the right position. The participants stated that their preference was to use natural light because they could feel better due to the windows in the hospital. For example, a 30-year-old participant (P14) uttered that: “I myself cope with natural lights much more. I mean I actually prefer to use natural light when it is daylight than artificial light, so I feel better.”

  • Preference to Use Light Bulbs with White Light: One of the subcategories raised by the study participants was preference to use light bulbs with white light. In this sense, Participant P17 said that: “White and moonlight color are good, but I do not like yellow for light bulbs at all. The feeling it gives me with sunlight is not a good one; that is, if I want to choose light bulbs for my home, I will prefer moonlight ones.” Unlike most participants, a few favored sunlight light bulbs. For example, Participant P16 stated that: “The experience that I have bout portable or local light bulbs is better. Yellow lights are better, because I have seen that such light bulbs hardly ever irritate the eyes.”

  • Discouragement Following the Use of Non-Harmonious Colors: The last subcategory was discouragement following the use of non-harmonious colors. In this regard, a participant (P14) expressed that the use of colors without considering order and proportion could start discouragement, as: “For example, look at the door. It does not match the colors all over the place. It has one color, but the frame is another color, and even the walls, the ceiling, the sideboards are all in different colors. They are out of place and the colors seem to be unbalanced. The door is brown, and the frame is cream. They have no harmony. I think they do not fit. Even though these designs are many times beautiful, but here it is more mixed up. It is more boring. In general, they do not use a combination of colors, and even do not care about harmony, order, and proportionality between colors.” In this regard, another participant (P17) with two years of working experience stated that the disproportion between colors could make the environment look messy and disturb its balance, as: “Without doubt, it is much better if there is a color that matches the rest used in the hospital wards. If one color is applied on the walls, for example, green, but a mismatched color on the floor, they do not go with green, and this will not work, which means it is not preferable. It is always based on the use of a set of colors from the same family. As an example, if the walls are in light green, the floor should be in a darker spectrum, so that they reach a harmony. In my opinion, anything far from balance leads to confusion and imbalance, thereby affecting the surrounding environment.”

Satisfaction with combined or portable lighting according to work and time

Among other categories obtained in this study was satisfaction with combined or portable lighting according to work and time, which could be effective in WVC among the hospital staff, with four subcategories of (i) a sense of satisfaction with using local and portable light bulbs, (ii) satisfaction with combined lighting, (iii) necessity of ambient light, and (iv) light intensity according to type of activities and working shifts.

  • A Sense of Satisfaction with Using Local and Portable Light bulbs: The use of portable or local light bulbs was very practical in the hospital wards and the hospital staff members were highly satisfied with the ability to move and change the light bulbs. In this context, Participant P16 stated that: “Portable light bulbs that only flash light on certain parts, especially in the examination and venipuncture rooms, are currently used a lot, and we feel satisfied.”

  • Satisfaction with Combined Lighting: The study participants expressed their satisfaction with the combination of sunlight and moonlight light bulbs among other factors that could facilitate WVC. Participant P7 affirmed that: “It is much better if the colors of the light bulbs are mixed. Now, it is better if the sunlight and moonlight ones are combined. This way it is closer to sunlight or natural light, so it is now much more popular.” Necessity of Ambient Light. Another subcategory was the necessity of ambient light. In this regard, Participant P16 put emphasis on light intensity that needed to be distributed and uniform. On the topic of the arrangement of the light bulbs, it was also added that: “I prefer to arrange the light bulbs in such a way that there are as few dark spots as possible to work at ease.”

  • Light Intensity according to Type of Activities and Working Shifts: Among the other subcategories was the necessity of balance between light intensity and the type of activities and working shifts. In this line, a participant (P10) maintained that: “In my opinion, light intensity varies from a building or a house and a factory. There are different standards in the industry. For example, a laboratory should be much brighter because of much sensitivity in this working environment, but nothing will happen in this ward even if the light is low. In terms of choosing the type of light bulbs, their light intensity, distance to the floor, and color should be taken into account according to the type of activities and their sensitivity.”

Discussion

This research aimed to explore the obstacles and enablers associated with the WVC as perceived by hospital personnel. Findings revealed that Workplace Visual Comfort faces numerous challenges in the Iranian healthcare system, while also identifying the supporting elements present in hospital wards, which emerged from the primary themes of the study. (i) Lack of managerial attention to the work environment and standard lighting system design, (ii) Visual annoyance caused by unnatural inappropriate lighting system combined with a high workload, and (iii) A sense of visual comfort based on proper lighting. Meanwhile, WVC was of utmost importance to provide high-quality healthcare services and avoid any errors. WVC played a crucial role in delivering high-quality healthcare services while striving to minimize the occurrence of errors.

A significant theme explored in this study, which serves as an obstacle to the implementation of WVC, is the lack of attention to efficiency and structural design standards. Within this framework, various factors can be identified, including the design of non-standard components related to surface texture, light glare, thermal stress, the absence of replacement options, and the inferior quality of lighting fixtures, as well as the general awareness regarding lighting practices. Perumal et al. (2021) have identified light glare and other manifestations of visual discomfort as non-standard factors that can significantly impact the visual experience29. Toodekharman et al. (2023) undertook a study examining the effects of lighting conditions, demonstrating that inadequate lighting systems can lead to eye irritation, diminished visual acuity, and, in some instances, may result in headaches and dryness of the eyes30. A separate study regarding visual comfort in pediatric oncology intensive care units found that light reflections contribute to about 14.6% of the discomfort experienced by participants31. According to research, Leyk (2018) discovered that the combination of high workplace temperatures and physical labor can cause considerable stress on different systems in the human body, resulting in a sudden decline in performance and potential health risks32. In the area of lighting equipment replacement, Pardabekovich (2021) found that the design of effective lighting could greatly influence workplace efficiency, which is consistent with the results of the current study33.

Furthermore, the study highlighted that eye injuries related to unnatural light exposure and excessive workloads were significant concerns. Among the obstacles to workplace visual comfort (WVC) reported by hospital staff were inappropriate levels of light intensity in the wards, which could lead to vision damage, fatigue, discomfort, and reduced accuracy and focus during tasks. The findings indicated that 73% of participants in Lima et al. (2023) believed the ambient light to be adequate and sufficient, while 22% recognized that the ambient light was either too low or too high31. According to Zhang and Qu (2019), prolonged exposure to high lighting levels can significantly impact hypertrophy in normal eyesight over a four-week period34. In this regard, Perumal et al. (2021) found that consistently bright work environments could diminish alertness, causing individuals to become fatigued more rapidly29. Schledermann et al. also noted that excessive lighting and the reflections from glassy walls in corridors and patient rooms could create discomfort due to heightened brightness35. In relation to low light intensity, Jackett and Frith (2013) similarly observed that optimal lighting is characterized by a clear view. An abundance or deficiency of lighting in any work setting can thus lead to various discomforts and even accidents36. As indicated by previous studies and the current research, individuals have differing preferences regarding light range and intensity. Therefore, it is advisable to employ a moderate light intensity in ward designs to enhance the satisfaction levels of hospital staff during medical procedures.

A recent study has identified an obstacle to visual comfort: the rise in error rates attributed to heavy workloads and extended shifts, which negatively affects accuracy and visual concentration. Nurses regard light as a crucial environmental factor that contributes to errors in acute care, alongside noise, ergonomics, furniture, equipment, and spatial layout37. Research indicates that medical errors often stem from human mistakes, influenced by the interaction between user environments and conditions like workplace lighting. In other words, environmental elements and thoughtfully designed strategies directly impact the reduction of errors38,39. Moreover, one study emphasizes the significance of lighting in preventing mistakes and enhancing patient safety; lighting conditions in the workplace are vital for nurses when making decisions about patient care. Therefore, nurses require adequate support in their work environment, including proper lighting and related training, to ensure patient safety40. Huisman et al. (2012) noted that effective lighting in hospital wards can assist in diagnosis, enhance care delivery, support rehabilitation, and even alleviate stress while reducing medical errors41. As highlighted in several studies and the latest findings presented here, fatigue from extended work shifts combined with insufficient ambient light can negatively impact the accuracy and focus of hospital staff during medical procedures and patient monitoring, thereby increasing the likelihood of errors.

Among the identified factors that hinder visual comfort, sleep disorders resulting from shift work are noteworthy. Daylight and colour temperature significantly influence Circadian Rhythm Sleep Disorders (CRSD). An inadequate lighting system can trigger melatonin release at inappropriate times, leading to sleep issues and dizziness. While advocates of full-spectrum fluorescent lights claim that this type of lighting mimics natural light and offers health and performance benefits, the evidence backing this assertion is lacking39. Additionally, Figueiro et al. (2014) demonstrated that the quality of sleep and nighttime circadian rhythms could be positively impacted through ambient light interventions. By adjusting lighting intensity and other parameters according to need, they succeeded in enhancing the sleep conditions of the participants42. It was discovered that among the factors contributing to eye irritation and disruptions in sleep rhythms among shift nurses, an unstructured work schedule combined with exposure to unnatural lighting was a significant influence. Even after modifying the daylight by changing the lighting sources, staff members reported feelings of sleepiness and a lack of focus.

One notable discovery related to the visual comfort of nurses in this research was the theme “A sense of visual comfort based on proper lighting.” The respondents emphasized that when designing the building, standard colors and suitable lighting should be incorporated, along with windows to allow natural light in certain areas, fostering a sense of both satisfaction and discomfort. In this context, research has indicated that both natural and artificial lighting should play a role in the design of healthcare facilities to enhance various spaces according to the requirements of patients, doctors, and staff31,43. A study by Khaleghimoghaddam (2023) highlighted the importance of incorporating windows in building design to achieve well-lit interior environments, facilitating the entry of natural light into the workplace, which in turn promotes relaxation and thermal comfort (37). The findings suggest that having natural light available through windows is vital for the comfort of employees engaged in procedures and other tasks43. The relaxation experienced by the medical staff during their shifts can also be attributed to the architectural design, which incorporates harmonious colors and a mix of lighting sources. Numerous studies indicate that an inadequate lighting setup in hospital environments adversely impacts patients’ well-being. Research by Lima et al. (2023) highlighted that the inclusion of yellow hues in light fixtures, combined with insufficient lighting intensity in critical care areas due to high workloads and a need for prompt responses from staff, can contribute to increased emotional stress31. While there is not a universal agreement on specific color selections, the findings suggest that adhering to architectural principles in lighting design, along with addressing lighting conditions appropriate to the architecture, could lead to improved satisfaction for both staff and patients.

Another observation that contributed to nurses feeling content and at ease during their work was the presence of natural light, along with the use of portable and localized lighting equipment as needed according to the type of task and various work shifts. In this regard, most participants in Davis et al.‘s study noted that they require additional lighting during procedures37. Furthermore, Ziabari et al.‘s study (2023) revealed a direct correlation between ambient lighting and job burnout, indicating that increased access to daylight could diminish burnout levels (p = 0.018, OR = 0.910)44. It was determined that having access to natural light results in positive effects, and in situations where natural light is lacking or insufficient, the necessity for supplemental and portable lighting becomes essential for executing tasks that demand high precision and focus.

Conclusion

The qualitative findings of this study illuminated several critical barriers to visual comfort in hospital settings from the perspectives of nursing and clinical staff. First, organizational indifference was a dominant theme; participants consistently noted insufficient managerial attention to lighting standards and environmental design, largely due to limited understanding of the role of visual ergonomics in clinical performance and staff well-being. Second, environmental challenges—including inadequate or poorly maintained lighting systems—directly impaired visual perception, particularly in high-stakes units such as emergency and critical care wards. Third, occupational stressors such as extended shifts, particularly night shifts, and high workload were perceived to intensify visual fatigue, compromising both comfort and patient safety. These results underscore the need for interdisciplinary collaboration between hospital administrators, occupational health specialists, and nursing managers to address visual discomfort in clinical environments. Interventions should go beyond technical lighting improvements and incorporate staff education, participatory design processes, and policy-level engagement. It is recommended that hospital occupational health personnel be formally included in clinical governance and decision-making committees where environmental and ergonomic standards are discussed. Furthermore, the Ministry of Health should develop national guidelines that mandate ergonomic lighting standards in hospital environments, particularly in units with high visual demands.