## 6 Discussion
It is possible to use task lighting to support activities while maintaining melanopic EDI below 10 lux [77]. Our systematic review revealed diverse study samples that ranged from those with disrupted circadian rhythms, mood disorders in ICUs and CCUs, individuals with dementia or cognitive impairments, elderly residents in nursing homes, and nurses working in healthcare settings. There are, however, limitations associated with small sample sizes. Considering the small number of participants, the results may not be generalizable. It is therefore recommended to interpret the results of studies with limited sample sizes with caution and to be aware of the potential biases that could result. The studies identified in this systematic review provided initial and potentially valuable insights into the effects of lighting conditions on patient-related health outcomes. However, further research should be conducted with larger samples to confirm and extend their conclusions. The approaches of the reviewed papers to the lighting designs in healthcare settings can be broadly categorized into two groups: simulation-based and human case interventions. Considering the limited number of simulation-based studies in healthcare environments, it is challenging to identify the most effective tools. The human intervention studies further delineate into five distinct dimensions--sleep-related, mood and psychological, patient-related, nurse-related, and environmental and psychosocial health outcomes. An important aspect of evaluating these results is recognizing the importance of critically reviewing all evidence to determine if it is effective in answering key research questions: lighting design influences health outcomes in healthcare settings, whether the results are appropriate for the study design and sample, and how easily recommendations can be implemented in a wide variety of environments, populations, and circumstances. Whereas an abundance of neuroscience and biological evidence underscores the profound impact of natural light on human health and well-being, encompassing benefits such as fatigue mediation, improved alertness in health providers, and positive environmental experiences for patients and their families, the reviewed papers present a mixed outlook on the benefits of artificial lighting in terms of health outcomes. Although some advocate for the potential benefits of adjustable lighting mimicking natural light, others report conflicting or inconclusive results. In order to understand how artificial lighting designs affect the occupants of healthcare facilities, more rigorously controlled interventions and comprehensive experiments within controlled institutional environments are necessary. It will offer the chance to consider the multifaceted influences of various parameters on circadian health. Despite significant technological advancements in the electric lighting market, bench scientific studies, and the daylighting and building automation sectors, a noteworthy observation from the reviewed papers is the continued independence of these sectors. This lack of integration hinders the realization of healthier environments for patients and night-shift medical staff. Integrating these sectors, however, offers a dual advantage: it enhances user-centered lighting, particularly for patients and nurses, contributing significantly to improved health outcomes. Additionally, this integration provides an opportunity for a thorough post-occupancy evaluation (POE) that incorporates both technical environmental assessment (TEA) and observer-based environmental assessment (OBEA) simultaneously. TEA involves objective measurements and technical assessments, encompassing metrics like illuminance levels, color temperature, and spectral distribution to provide quantitative data on the physical aspects of lighting. In contrast, OBEA relies on subjective assessments from healthcare staff or patients, capturing perceptions, preferences, and qualitative feedback.