Light deprivation and consequences on well-being
In architecture, light becomes an important regulatory element for living comfort, so much so that the problem arises when the design of spaces does not take it into account by reducing access to natural light. Deep offices, schools with insufficient openings, shielded homes, long working hours and seasons with reduced sunshine lead to light exposure that is not consistent with the solar rhythm.
Studies published on Journal of Clinical Endocrinology & Metabolism, international scientific journal published by the Endocrine Society, based in the United States, e Sleep Medicine Reviewsan international scientific journal published by Elsevier, based in the Netherlands, show how the deprivation of natural daylight and excess artificial light in the evening are associated with sleep disturbances, decreased attention, mood alterations and increased perceived stress.
In the workplace, research conducted by Lighting Research Center at Rensselaer Polytechnic Institute (USA), for example, have highlighted that “circadian friendly” lighting systems, by modulating the light intensity and color temperature over the course of the day to imitate the natural pattern of the sun, improve the quality of sleep of employees and reduce daytime drowsiness. Likewise, a study published in Building and Environment (ed. Elsevier) correlated adequate exposure to natural light in offices with better cognitive performance and less visual fatigue.
Circadian technology and design
If the building is an interface between the environment and the psychophysical system, light therefore represents one of its most sensitive membranes. We cannot always guarantee correct FLDm (Average Daylight Factor) in every environment, in overcast conditions or in optimal orientations. However, technology today allows the integration of Building Automation systems capable of dynamically modulating light intensity and color temperature.
A lighting design approach that focuses not only on visual performance but on the biological and psychological response of the human being, artificially reproduces the evolution of the sky: cold and more intense shades in the morning (5000-6500 K), progressive neutralization in the central hours, up to warmer temperatures and reduced levels in the late afternoon and evening (2700-3000 K). This modulation is physiological.
By maintaining a coherent alternation of light stimuli, the synchronization between cortisol and melatonin secretion is preserved, reducing the risk of circadian misalignment.
Regulations and design responsibility
Technical regulations for homes, workplaces and schools are not aligned with scientific research. Today we are talking about circadian metrics, already well present in some international protocols such as the Well Building Standard. They are parameters that measure how much a light stimulates the human circadian system, not just how much it visually illuminates.
Designing light therefore means integrating photometric data, orientation, solar shading, surface reflectances and intelligent control systems. It means thinking of the building envelope as a regulator of light information and the window as a biological synchronizer.
In an era in which we spend over 90% of our time indoors, luminous comfort becomes a design responsibility. Thinking that it only serves to illuminate spaces is now beyond science. Light, if well governed, aligns the time of the body with the time of the world.
