Light for life

Written By Kieran Sikdar

My interest in health dates back to my childhood. In the 90s, I became an apprentice of sorts to my Indian grandfather, who lived with us for long stretches of time. A man of meticulous wellness routines, he taught me breathwork, yoga, and how to avoid the ancestral vice of sugar. But it wasn’t until a couple of years ago that my interest turned to light as a critical component of human health. When my partner developed an extreme and somewhat medically inexplicable, sensitivity to sunlight, I began digging into the work of Dr. Jack Kruse, a neurosurgeon who went through his own major health crisis that inspired him to advance the art of decentralized medicine. A practice of focusing on individual responsibility, environmental factors, and circadian biology. One of the main principles of his teaching is to get your light right:

Build a deeper connection to the sun and rid your life of the light that is harming it.

Screens and artificial light harm our health if not managed properly. The primary culprit is the artificial blue spectrum of light that disrupts our sleep, hormones, and brain in ways that limit human vitality and long-term productivity, especially in children.

Natural blue light from the sun promotes human health in many ways. Artificial blue light will keep you more alert and productive in the short term, but extended exposure, especially after sunset, bears negative consequences. For instance, blue light sends signals to your body that it is time to wake up and start your day. However, our bodies are designed to function according to the cycles of the sun, by which blue light decreases later in the day.

Thus, if you look at a screen without any filters or eye protection late in the day or even worse,  before bed, your body receives the message that it is time to wake up, leading to inadequate sleep. This, in turn, causes a cascade of negative health impacts. The good news is that you can take simple steps to mitigate the adverse effects of artificial blue light.

Here are just a few:

  • Use amber lighting on your devices, at least after sunset, or better yet, all the time.

  • Use grayscale on your device when color is not needed to reduce screen addiction.

  • Minimize screen brightness (without creating eye strain) to reduce stimulation.

  • When buying a new device with a screen,  consider technologies with low or no blue light, such as the Daylight Computer or E Ink phones and monitors.

  • Use blue light filtering glasses to reduce the impact of lights and screens after sunset.

  • Use light bulbs with minimal blue light after sunset (or always).

  • Minimize screen and artificial light use 1-2 hours before bed.

  • Minimize, and ideally eliminate screens and technology in the bedroom.

  • Sleep in a dark, quiet room and turn off as many electronic devices as possible.

  • Spend time outside, taking deep breaths of fresh air to offset the effects of the more shallow, restricted breathing that occurs during screen use.

  • Walk barefoot in nature to reduce stress and the negative impacts of artificial light.

  • Increase healthy exposure to the sun to optimize health, learning, and sleep:

    • Sun gaze (don’t stare) at sunrise for up to 1 hour, and again for 1 hour before sunset to jumpstart all kinds of healthy functions that don’t happen without this exposure including skin protection from UV rays later in the day.

    • How to sun gaze safely:

      • Look indirectly toward the sun without anything blocking your eyes, such as contacts, glasses, or windows. Try setting your gaze to 15 degrees away, but not closer, from the sun without squinting or straining.

      • Start with short stints of sun-gazing, building up over time, to allow your body to adjust and stay relaxed.

Below are short summaries of references for the topics above if you want to dive deeper into the science behind them. Please email me (kieran at justhomefree.com) if you have any questions, suggestions or if want to talk further. Please leave comments at the bottom as well. 

Annotated Bibliography: Morning Light Exposure in the Eyes and Hormonal Regulation

1. Foster, R. G., & Kreitzman, L. (2014).

The rhythms of life: The biological clocks that control the daily lives of every living thing. Yale University Press.

Annotation:
Foster and Kreitzman provide a comprehensive overview of how light exposure, particularly in the morning, regulates circadian rhythms through the eyes. They discuss how intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to morning light, signaling the suprachiasmatic nucleus (SCN) to regulate hormone secretion, including melatonin and cortisol. This process helps synchronize antioxidant production, reducing oxidative stress from later UV exposure. The book is a valuable resource for understanding how light influences the endocrine system, though it does not focus specifically on UV protection.

2. Gooley, J. J., Lu, J., Fischer, D., & Saper, C. B. (2003).

A broad role for melanopsin in nonvisual photoreception. Journal of Neuroscience, 23(18), 7093-7106. https://doi.org/10.1523/JNEUROSCI.23-18-07093.2003

Annotation:
This study explores the role of melanopsin-expressing retinal cells in regulating circadian rhythms. The authors explain how morning light exposure activates these cells, leading to cortisol release, which enhances alertness and regulates antioxidant responses. They also discuss how melanopsin signaling helps mitigate oxidative stress, indirectly protecting against UV-induced cellular damage. While the study provides strong neurobiological insights, it does not directly investigate long-term UV protection.

3. Brainard, G. C., Hanifin, J. P., Greeson, J. M., Byrne, B., Glickman, G., Gerner, E., & Rollag, M. D. (2001).

Action spectrum for melatonin regulation in humans: Evidence for a novel circadian photoreceptor. Journal of Neuroscience, 21(16), 6405-6412. https://doi.org/10.1523/JNEUROSCI.21-16-06405.2001

Annotation:
Brainard et al. provide key evidence that blue light in the morning effectively suppresses melatonin and enhances cortisol production. The study demonstrates that exposure to early daylight regulates oxidative stress defense mechanisms, helping the body prepare for later UV exposure. This research is crucial in linking ocular light exposure to circadian-controlled antioxidant production, though it does not explicitly connect these findings to skin protection.

4. Hattar, S., Liao, H. W., Takao, M., Berson, D. M., & Yau, K. W. (2002).

Melanopsin-containing retinal ganglion cells: Architecture, projections, and intrinsic photosensitivity. Science, 295(5557), 1065-1070. https://doi.org/10.1126/science.1069609

Annotation:
This foundational paper identifies melanopsin-containing retinal ganglion cells (ipRGCs) and their role in regulating circadian rhythms. The authors discuss how these cells are directly activated by morning sunlight, signaling the SCN to regulate hormone production. The study is significant for understanding how ocular light exposure influences systemic antioxidant responses, which may contribute to UV resilience. However, it does not explore the direct protective effects on the skin.

5. Turner, P. L., & Mainster, M. A. (2008).

Circadian photoreception: Ageing and the eye’s role in systemic health. British Journal of Ophthalmology, 92(11), 1439-1444. https://doi.org/10.1136/bjo.2008.141747

Annotation:
This review examines how the aging eye affects circadian photoreception, emphasizing the importance of morning light exposure in regulating melatonin suppression, cortisol release, and antioxidant defense mechanisms. The authors highlight that reduced light perception with age can impair these hormonal responses, potentially increasing oxidative stress and UV vulnerability. The study is useful for understanding age-related changes in ocular light processing, though it does not focus exclusively on UV protection.

  

 Annotated Bibliography: Early Sun Exposure and Melanin Production

1. Slominski, A. T., Kim, T. K., Brożyna, A. A., Janjetovic Z., Brooks D.L., Schwab L.P., Skobowiat C., Jozwicki W., Seagroves T.N (2014). The role of melanogenesis in regulation of melanoma behavior: Melanogenesis leads to stimulation of HIF-1alpha expression and HIF-dependent attendant pathways. Arch. Biochem. Biophys. https://doi.org/10.1016/j.abb.2014.06.030

Annotation:
This study examines how melanin functions as a natural photoprotective mechanism, absorbing and scattering UV radiation. The authors highlight that early sun exposure stimulates melanogenesis, which enhances the skin’s ability to withstand subsequent UV exposure. The paper provides a molecular perspective on melanin’s role in DNA repair and oxidative stress reduction.

2. Glickman, R. D. (2002).

Phototoxicity to the retina: Mechanisms of damage and protection. International Journal of Toxicology, Nov-Dec;21(6):473-90. https://doi.org.10.1080/10915810290169909

Annotation:
Glickman’s study, while primarily focused on retinal damage, discusses the broader biological responses to UV exposure, including melanin's protective properties. It explains how early morning sun exposure, with lower-intensity UVB, can prime the skin’s defense mechanisms without causing excessive oxidative stress.

3. Plonka, P. M., Passeron, T., Brenner, M., Tobin, D. J., Shibahara, S., & Thomas, A. (2009).

What are melanocytes really doing all day long...? Experimental Dermatology, 18(9), 799-819. https://doi.org/10.1111/j.1600-0625.2009.00912.x

Annotation:
This review explores the circadian regulation of melanocytes and how sunlight exposure influences melanin synthesis. The authors suggest that morning light exposure may be optimal for initiating melanin production while minimizing DNA damage from high-intensity midday UV. The study supports the idea that early exposure helps prepare the skin for later sun exposure.

4. Panda, S. (2016).

Circadian physiology of metabolism. Science, 354(6315), 1008-1015. https://doi.org/10.1126/science.aah4967

Annotation:
While not directly about melanin, this paper discusses the role of circadian rhythms in skin physiology, emphasizing how light exposure at different times of the day affects metabolic and hormonal processes. Panda's research suggests that morning sun exposure may synchronize melanin production with the body's natural repair mechanisms, enhancing UV protection. This article is valuable for understanding the timing aspect of sun exposure but does not focus solely on skin photobiology.

5. Hoel, D. G., Berwick, M., de Gruijl, F. R., & Holick, M. F. (2016).

The risks and benefits of sun exposure 2016. Dermato-Endocrinology, 8(1), e1248325. https://doi.org/10.1080/19381980.2016.1248325

Annotation:
This paper presents a balanced discussion of the health effects of sun exposure, including both the benefits of early sunlight exposure for vitamin D production and melanin stimulation, and the risks of excessive UV exposure. The authors suggest that controlled morning sun exposure provides protective benefits by activating adaptive responses without triggering significant DNA damage. The study is useful for understanding the trade-offs of sun exposure, but it does not provide experimental data on optimal exposure times.


 

Annotated Bibliography: The Health Benefits of Morning Sun Gazing

1. Foster, R. G., & Kreitzman, L. (2014).

The rhythms of life: The biological clocks that control the daily lives of every living thing. Yale University Press.

Annotation:
This book provides a comprehensive overview of circadian rhythms and their relationship with morning light exposure. The authors explain how sun gazing at sunrise helps regulate the body’s internal clock, improving sleep patterns, hormonal balance, and overall well-being. The text discusses how morning sunlight activates melanopsin-expressing retinal cells, signaling the suprachiasmatic nucleus (SCN) to optimize metabolic and neurological processes. This book is an excellent resource for understanding the broader physiological benefits of morning sunlight, though it does not focus specifically on sun gazing techniques.

2. Hattar, S., Liao, H. W., Takao, M., Berson, D. M., & Yau, K. W. (2002).

Melanopsin-containing retinal ganglion cells: Architecture, projections, and intrinsic photosensitivity. Science, 295(5557), 1065-1070. https://doi.org/10.1126/science.1069609

Annotation:
This foundational study identifies melanopsin-containing retinal ganglion cells (ipRGCs) and their critical role in responding to morning light. The researchers show that sun gazing at dawn activates these cells, leading to melatonin suppression, cortisol release, and enhanced alertness. The study is crucial in explaining the biological mechanisms of morning light exposure, but it does not discuss the specific practice of sun gazing as a health ritual.

3. Rüger, M., & Scheer, F. A. (2009).

Effects of circadian disruption on the cardiometabolic system. Reviews in Endocrine & Metabolic Disorders, 10(4), 245-260. https://doi.org/10.1007/s11154-009-9122-8

Annotation:
This review explores the consequences of circadian misalignment on hormone production and metabolic health. The authors highlight the protective effects of morning light exposure, including improved insulin sensitivity, reduced oxidative stress, and better cardiovascular health. The study indirectly supports sun gazing as a method for reinforcing a strong circadian rhythm, though it does not discuss the practice explicitly.

4. Hoel, D. G., Berwick, M., de Gruijl, F. R., & Holick, M. F. (2016).

The risks and benefits of sun exposure 2016. Dermato-Endocrinology, 8(1), e1248325. https://doi.org/10.1080/19381980.2016.1248325

Annotation:
This paper examines the health effects of sun exposure, weighing the risks and benefits. The authors argue that moderate morning sunlight exposure, such as sun gazing, provides significant benefits by stimulating vitamin D production, enhancing immune function, and reducing the risk of chronic diseases. The study emphasizes that morning sunlight is less intense and poses lower risks of UV-induced skin damage, making it an ideal time for controlled sun exposure.

5. Reiter, R. J., Rosales-Corral, S., Tan, D. X., Jou, M. J., Galano, A., & Xu, B. (2017).

Melatonin as a mitochondria-targeted antioxidant: One of evolution’s best ideas. Cellular and Molecular Life Sciences, 74(21), 3863-3881. https://doi.org/10.1007/s00018-017-2609-7

Annotation:
This study discusses the antioxidant properties of melatonin and how morning sunlight influences its regulation. The authors describe how morning sun gazing helps balance melatonin production, promoting cellular repair, anti-aging effects, and UV protection. The research provides strong biochemical evidence for the protective effects of morning light on oxidative stress and inflammation, supporting the practice of sun gazing for overall health.

6. Huberman, A. D. (2021).

The science of light and its impact on the brain. Huberman Lab Podcast.

Annotation:
Neuroscientist Andrew Huberman discusses the neurological and psychological benefits of morning light exposure. He explains how viewing natural sunlight early in the day regulates dopamine, serotonin, and cortisol, contributing to improved mood, motivation, and mental clarity. His insights support morning sun gazing as a practice for enhancing brain function, though his research does not specifically focus on sun gazing techniques.

7. Figueiro, M. G., & Rea, M. S. (2010).

Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students. Neuro Endocrinol Lett. 2010;31(1):92-6. https://pubmed.ncbi.nlm.nih.gov/20150866/

Annotation:
This study investigates the role of blue light from natural sunlight in regulating circadian rhythms. The authors emphasize that morning sun gazing exposes the eyes to beneficial short-wavelength light, which helps suppress melatonin at the right time and enhances wakefulness. Their findings suggest that lack of morning light exposure can lead to circadian misalignment and increased oxidative stress, making early sun exposure an essential daily practice.

Annotated Bibliography: UVA Exposure, Vitamin D Deficiency, and Melanoma Risk

1. Garland, C. F., Gorham, E. D., Mohr, S. B., & Garland, F. C. (2009).

Vitamin D for cancer prevention: Global perspective.
Annals of Epidemiology, 19(7), 468-483. https://doi.org/10.1016/j.annepidem.2009.03.021

Annotation:
This study examines the relationship between vitamin D deficiency and cancer risk, emphasizing its protective role in melanoma prevention. The authors argue that increased UVA exposure without adequate UVB-driven vitamin D synthesis may contribute to rising melanoma rates. The paper supports moderate, non-burning sun exposure as a safer approach to balancing vitamin D production and skin protection.

2. Moan, J., Porojnicu, A. C., Dahlback, A., & Setlow, R. B. (2008).

Addressing the health benefits and risks, involving vitamin D or skin cancer, of increased sun exposure.
Proceedings of the National Academy of Sciences, 105(2), 668-673. https://doi.org/10.1073/pnas.0710615105

Annotation:
This study explores the paradox of sun exposure, showing that UVB exposure is essential for vitamin D synthesis, while excessive UVA exposure is linked to melanoma. The researchers found that countries with high sunscreen use (which blocks UVB) have higher melanoma rates, suggesting that sunscreen-induced vitamin D deficiency could contribute to cancer risk. The study recommends sunscreens that balance UVA/UVB protection to prevent melanoma without suppressing vitamin D synthesis.

3. Lindqvist, P. G., Epstein, E., Nielsen, K., Landin-Olsson, M., & Ingvar, C. (2014).

Avoidance of sun exposure is a risk factor for all-cause mortality: A cohort study.
Journal of Internal Medicine, 276(1), 77-86. https://doi.org/10.1111/joim.12251

Annotation:
This long-term study found that women who avoided sun exposure had twice the mortality rate compared to those with higher sun exposure. The findings suggest that vitamin D deficiency due to reduced UVB exposure may increase the risk of various diseases, including melanoma. The study challenges current sun-avoidance recommendations, arguing that controlled sun exposure may offer health benefits outweighing melanoma risks.

4. Juzeniene, A., & Moan, J. (2012).

Beneficial effects of UV radiation other than via vitamin D production.
Dermato-Endocrinology, 4(2), 109-117. https://doi.org/10.4161/derm.20013

Annotation:
This study explores other potential benefits of UV exposure beyond vitamin D, including nitric oxide release (which improves cardiovascular health) and immune system modulation. The authors discuss how UVA exposure alone, without adequate UVB exposure for vitamin D synthesis, may increase melanoma risk. The findings support a balanced sun exposure strategy rather than strict sun avoidance.

5. Reichrath, J. (2006).

The challenge resulting from positive and negative effects of sunlight: How much solar UV exposure is appropriate to balance between risks of vitamin D deficiency and skin cancer?
Progress in Biophysics and Molecular Biology, 92(1), 9-16. https://doi.org/10.1016/j.pbiomolbio.2006.02.010

Annotation:
This review examines the complex relationship between UV exposure, vitamin D synthesis, and skin cancer risks. The author emphasizes that excessive UVA exposure may contribute to melanoma, while UVB exposure plays a dual role—both increasing the risk of sunburn and producing vitamin D, which helps protect against melanoma. The study suggests rethinking sun exposure guidelines to maximize vitamin D benefits while minimizing UVA damage.

Annotated Bibliography: Morning Sun Exposure and Its Impact on Brain Health, Learning, and Child Development

1. LeGates, T. A., Fernandez, D. C., & Hattar, S. (2014).

Light as a central modulator of circadian rhythms, sleep, and affect. Nat Rev Neurosci. 2014 Jul;15(7):443-54. https://doi.org/10.1038/nrn3743

Annotation:
This study explores the role of morning light exposure in regulating circadian rhythms, mood, and cognitive function. The researchers found that light exposure in the early morning activates intrinsically photosensitive retinal ganglion cells (ipRGCs), which signal the brain’s suprachiasmatic nucleus (SCN) to regulate sleep-wake cycles and neurotransmitter production. These findings support the hypothesis that morning sunlight exposure enhances brain function, improves mood, and optimizes learning by aligning circadian rhythms.

2. Rüger, M., & Scheer, F. A. (2009).

Effects of circadian disruption on the cardiometabolic system.
Reviews in Endocrine & Metabolic Disorders, 10(4), 245-260. https://doi.org/10.1007/s11154-009-9122-8

Annotation:
This review examines how disruptions to the natural light-dark cycle impair cognitive function, metabolic health, and mood regulation. The authors emphasize that morning sunlight exposure helps regulate cortisol levels, enhancing alertness, learning capacity, and overall brain function. The study highlights the importance of early morning light in stabilizing circadian rhythms, particularly in children, to improve attention and learning outcomes.

3. Foster, R. G., & Kreitzman, L. (2014).

The rhythms of life: The biological clocks that control the daily lives of every living thing.
Yale University Press.

Annotation:
This book discusses the relationship between light exposure, circadian rhythms, and cognitive performance. The authors highlight that morning light exposure plays a critical role in setting the body’s biological clock, which influences hormone release, mood regulation, and brain function. The book supports the argument that consistent morning sunlight exposure in children enhances learning and brain development by aligning circadian rhythms.

4. Panda, S. (2016).

Circadian physiology of metabolism.
Science, 354(6315), 1008-1015. https://doi.org/10.1126/science.aah4967

Annotation:
This study highlights how light exposure in the morning regulates dopamine and serotonin production, which are essential for cognitive function and emotional well-being. The findings suggest that morning sun exposure through the eyes can enhance focus, learning, and overall brain development in children by promoting optimal neurotransmitter balance. The study supports exposing children to natural sunlight early in the day to support academic performance and emotional stability.

5. Chellappa, S. L., Steiner, R., Blattner, P., Oelhafen, P., Götz, T., & Cajochen, C. (2011).

Non-visual effects of light on melatonin, alertness, and cognitive performance: Can blue-enriched light keep us alert? PLoS One. 2011 Jan 26;6(1):e16429. https://doi.org/10.1371/journal.pone.0016429

Annotation:
This study examines the cognitive effects of blue-enriched morning light. The researchers found that exposure to natural blue light in the early morning enhances alertness, improves cognitive function, and aligns the circadian rhythm for better learning and retention. These findings reinforce the importance of early morning sunlight in boosting brain performance in both children and adults.

6. Berson, D. M., Dunn, F. A., & Takao, M. (2002).

Phototransduction by retinal ganglion cells that set the circadian clock.
Science, 295(5557), 1070-1073. https://doi.org/10.1126/science.1067262

Annotation:
This foundational study identifies the function of melanopsin-containing retinal ganglion cells (ipRGCs) in regulating circadian rhythms. The authors found that morning light exposure is essential for synchronizing the body’s internal clock, which affects sleep quality, learning ability, and mood stability. The study supports the argument that morning sunlight exposure plays a vital role in brain health and child development.

7. Huberman, A. (2021).

The science of light and its impact on the brain.
Huberman Lab Podcast.

Annotation:
Neuroscientist Andrew Huberman discusses the neurological effects of morning sunlight exposure on dopamine, serotonin, and cognitive function. He explains that viewing sunlight in the morning helps set the body’s circadian clock, which improves attention, learning ability, and overall brain performance. The discussion supports morning light exposure as a simple yet effective strategy for enhancing academic performance and brain development in children.

8. Wright, K. P., McHill, A. W., Birks, B. R., Griffin, B. R., Rusterholz, T., & Chinoy, E. D. (2018).

Entrainment of the human circadian clock to the natural light-dark cycle.
Current Biology, 23(16), 1554-1558. https://doi.org/10.1016/j.cub.2013.06.039

Annotation:
This study demonstrates that exposure to natural morning light enhances cognitive function and helps regulate sleep-wake cycles. The researchers found that individuals exposed to morning sunlight had better focus, faster reaction times, and improved learning capacity compared to those with minimal light exposure. These findings highlight the importance of natural morning light for childhood brain development and learning.

 

Annotated Bibliography: Screen Apnea – The Impact of Screen Use on Breathing and Health

Screen apnea refers to the phenomenon where people unconsciously hold their breath or breathe shallowly while using screens, leading to stress, reduced oxygenation, and long-term health effects. This annotated bibliography explores research on how screen use affects breathing, stress responses, and overall well-being.

1. Nestor, J. (2020).

Breath: The new science of a lost art.
Riverhead Books.

Annotation:
Nestor examines the science of breathing and how modern habits, including prolonged screen use, negatively impact respiratory function. He discusses screen apnea, where individuals unconsciously hold their breath or breathe irregularly while using digital devices, leading to stress, fatigue, and poor cognitive performance. The book emphasizes conscious breathing techniques to counteract screen-induced breathing issues, making it relevant for those seeking solutions to screen apnea.

2. Zomorodi, M. (2023, November 28). How screen time affects your breathing and stress levels. NPR. Retrieved from https://www.npr.org/transcripts/1247296780

Annotation:
This NPR episode explores the phenomenon of screen apnea, a term coined by Linda Stone to describe the unconscious breath-holding or shallow breathing people experience while using screens. Stone, a former Apple and Microsoft executive, initially observed this in herself before conducting informal research with volunteers. Her findings revealed that most people unknowingly hold their breath while working on digital devices, except for individuals trained in breath control, such as musicians, dancers, and military pilots.

The discussion highlights the physiological consequences of screen apnea, including increased stress, disrupted oxygen-carbon dioxide balance, and potential links to chronic diseases. The episode also features insights from James Nestor, author of Breath: The New Science of a Lost Art, who explains how poor breathing habits can contribute to anxiety, cognitive impairment, and even cardiovascular disease. He provides practical strategies to counteract screen apnea, such as slow, nasal breathing and maintaining proper posture.

 

Annotated Bibliography: The Health Impacts of Blue Light and Strategies for Mitigation

1. Chellappa, S. L., Steiner, R., Blattner, P., Oelhafen, P., Götz, T., & Cajochen, C. (2011).

Non-visual effects of light on melatonin, alertness, and cognitive performance: Can blue-enriched light keep us alert? PLoS One. 2011 Jan 26;6(1):e16429. https://doi.org/10.1371/journal.pone.0016429

Annotation:
This study examines the effects of blue-enriched light on melatonin suppression, alertness, and cognitive function. The researchers found that exposure to artificial blue light enhances short-term alertness and performance but suppresses melatonin, disrupting sleep quality in the long term. These findings support the text’s claim that blue light can increase productivity in the short term but has negative effects when used at night. The study underscores the importance of blue light filtering and reducing screen exposure before bedtime.

2. Tähkämö, L., Partonen, T., & Pesonen, A. K. (2018).

Systematic review of light exposure impact on human circadian rhythm.
Chronobiology International, 36(2), 151-170. https://doi.org/10.1080/07420528.2018.1527773

Annotation:
This systematic review analyzes how artificial and natural light exposure influences circadian rhythms. The authors confirm that morning sunlight is critical for setting the body’s internal clock, whereas artificial blue light at night disrupts circadian rhythms and leads to sleep disturbances. These findings support the text’s recommendation to increase exposure to natural sunlight while minimizing screen use before bed. The study also highlights the importance of using blue-light blocking glasses and warm-colored lighting in the evening.

3. Spitschan, M. (2019).

Melanopsin contributions to non-image-forming visual function and human health.
Curr Opin Behav Sci., Dec;30:67-72. https://doi.org/10.1016/j.cobeha.2019.06.004

Annotation:
This paper discusses the role of melanopsin-containing retinal cells in regulating sleep, alertness, and hormonal rhythms. It explains how morning sun exposure supports healthy circadian alignment, whereas prolonged artificial light exposure at night disrupts melatonin production and contributes to metabolic disorders. The study strongly supports the text’s claim that sun gazing at sunrise helps regulate the body’s natural rhythm. However, it does not specifically address mitigation strategies such as blue light filtering technologies.

4. West, K. E., Jablonski, M. R., Warfield, B., Cecil, K. S., James, M., Ayers, M. A., Maida, J., Bowen, C., Sliney, D. H., Rollag, M. D., & Hanifin, J. P. (2011).

Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans. J Appl Physiol (1985). 2011 Mar;110(3):619-26. https://doi.org/10.1152/japplphysiol.01413.2009.

Annotation:
This study found that long-term exposure to artificial blue light at night alters circadian homeostasis, increases insulin resistance, and negatively impacts metabolism. The findings align with the text’s warning that artificial light exposure at night has negative long-term health effects. The study further supports using warm light bulbs and reducing screen brightness after sunset as strategies to protect sleep and metabolic health.

5. Prayag, A., Münch, M., Aeschbach, D., Chellappa, S. L., & Gronfier, C. (2019).

Light modulation of human clocks, wake, and sleep.
Clocks Sleep, 10(1), 100059. https://pubmed.ncbi.nlm.nih.gov/32342043/

Annotation:
This review highlights the impact of light on cognitive function and overall health, emphasizing that blue light exposure before bed leads to circadian misalignment, cognitive decline, and mood disturbances. The findings support the recommendation to minimize screen exposure at night and replace artificial lighting with warm, dim alternatives. The study also highlights the role of early morning sunlight exposure in improving mood and cognitive function, reinforcing the text’s claims about the benefits of sun gazing.

6. Viola, A. U., James, L. M., Schlangen, L. J., & Dijk, D. J. (2008).

Blue-enriched white light in the workplace improves self-reported alertness, performance, and sleep quality. Scand J Work Environ Health. 2008 Aug;34(4):297-306. https://doi.org/10.5271/sjweh.1268.

Annotation:
This study explores the effects of blue-enriched light in workplace environments. The researchers found that blue light exposure during the day improved alertness and productivity, while reducing symptoms of daytime sleepiness. These findings support the text’s claim that blue light can be beneficial in certain contexts, such as boosting productivity during the day, but should be avoided in the evening.

7. Cyr M, Artenie DZ, Al Bikaii A, Borsook D, Olson JA. (2022).

The effect of evening light on circadian-related outcomes: A systematic review.leep Med Rev. 2022 Aug;64:101660. https://doi.org/10.1016/j.smrv.2022.101660.

Annotation:
This study confirms that exposure to artificial light in the evening delays circadian rhythms, suppresses melatonin, and reduces sleep efficiency. The findings strongly align with the text’s warning about the harmful effects of nighttime screen use. The study supports strategies such as blue-light blocking glasses, reduced screen brightness, and minimal artificial light exposure before bed.

 

 

Annotated Bibliography: Greyscale vs. Color Screens and Dopamine Regulation in Screen Addiction

1. Montag, C., Sindermann, C., Becker, B., & Panksepp, J. (2016).

An affective neuroscience framework for the neurobiological underpinnings of internet addiction.
Frontiers in Psychology, 7, 1906. https://doi.org/10.3389/fpsyg.2016.01906

Annotation:
This paper explores how excessive screen use influences dopamine-driven reward pathways, leading to behavioral addiction similar to substance abuse. The study suggests that highly stimulating digital content—especially color-rich, dynamic screens—may enhance dopamine release, reinforcing compulsive screen use. While it does not compare grayscale vs. color screens directly, the findings imply that reducing visual stimulation, such as using grayscale mode, could reduce dopamine spikes and weaken compulsive engagement.

2. Alter, A. (2017).

Irresistible: The rise of addictive technology and the business of keeping us hooked.
Penguin Press.

Annotation:
In this book, Alter explores how digital technologies manipulate dopamine to keep users engaged. He discusses how colorful notifications, infinite scrolling, and high-contrast visuals contribute to screen addiction. The book suggests that reducing screen stimulation—such as switching to grayscale mode—can weaken the reward cycle and help people regain control over their screen habits. While not a scientific study, the book provides valuable insights into how tech companies design screens for maximum engagement.

3. Christakis, D. A., Ramirez, J. S. B., Ferguson, S. M., Ravinder, S., & Ramirez, J. M. (2018).

How early media exposure influences cognitive and neural development.
Nature Reviews Neuroscience, 19(5), 291-302. https://doi.org/10.1073/pnas.1711548115

Annotation:
This review explores how screen exposure, particularly in children, affects dopamine pathways and cognitive development. The authors note that high-contrast, rapidly changing visuals contribute to overstimulation of dopamine receptors, increasing compulsive screen behaviors. They suggest that lowering visual intensity, such as using grayscale mode, may reduce excessive engagement and promote healthier screen habits.

 

 

Annotated Bibliography: The Health Benefits of Walking Barefoot in Nature

Walking barefoot in nature, often called "earthing" or "grounding," is associated with numerous physiological and psychological health benefits, including reduced inflammation, improved mood, and enhanced nervous system regulation. This annotated bibliography compiles research on the effects of barefoot walking on health, stress reduction, and overall well-being.

1. Chevalier, G., Sinatra, S. T., Oschman, J. L., & Delany, R. M. (2012).

Earthing: Health implications of reconnecting the human body to the Earth's surface electrons.
Journal of Environmental and Public Health, 2012, 291541. https://doi.org/10.1155/2012/291541

Annotation:
This study explores how direct skin contact with the Earth’s surface can reduce inflammation, improve sleep, and enhance overall health. The researchers found that barefoot walking enables the transfer of free electrons from the Earth into the body, acting as a natural antioxidant and reducing oxidative stress. The findings support earthing as a potential therapeutic practice for reducing stress and improving cardiovascular health.

2. Ghaly, M., & Teplitz, D. (2004).

The biologic effects of grounding the human body during sleep as measured by cortisol levels and subjective reporting of sleep, pain, and stress.
Journal of Alternative and Complementary Medicine, 10(5), 767-776. https://doi.org/10.1089/acm.2004.10.767

Annotation:
This study examines the effects of grounding on cortisol regulation and stress levels. The researchers found that sleeping while grounded (in direct contact with the Earth) significantly reduced nighttime cortisol levels, leading to better sleep quality and reduced stress. The findings support the idea that walking barefoot in nature during the day could provide similar stress-reducing effects.

Kieran Sikdar
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