Blue light emitted by devices like smartphones, computers, and televisions is becoming a major factor disrupting our sleep cycles. Research reveals that a significant number of Americans use electronic devices close to bedtime, contributing to poor sleep quality. Reducing exposure to blue light, particularly in the evening, is a simple yet effective way to help your body prepare for restful sleep.

What Is Blue Light?

How Does Blue Light Impact Circadian Rhythms?

Circadian rhythms are 24-hour cycles that control essential bodily functions, including sleep. Light is the primary factor that aligns these rhythms with day and night. Historically, exposure to sunlight during the day helped set our body clocks, signaling when to be awake and when to sleep. However, the widespread use of artificial lighting and electronic devices has introduced more light exposure after dark, disrupting these natural cycles.

Blue light, in particular, has the strongest impact on circadian rhythms. During daylight hours, blue light helps us feel alert by stimulating the brain, raising body temperature, and increasing heart rate. But in the evening, exposure to blue light can confuse the body’s internal clock, suppressing melatonin—the hormone responsible for making us feel sleepy. As a result, our brains may remain in “daytime mode,” preventing us from winding down for the night.

Health Consequences Of Disrupted Sleep

Persistent disruption of circadian rhythms can lead to a range of health issues, including metabolic disorders, poor mental health, and increased risk for conditions like depression and anxiety. Furthermore, the inability to sleep well at night affects cognitive performance, mood, and overall well-being. Chronic exposure to blue light in the evening may significantly contribute to these negative health outcomes.

Devices That Emit Blue Light

Many common devices in our daily lives emit blue light, including:

- Smartphones and tablets

- Computer monitors and laptops

- Televisions and e-readers

- LED and fluorescent lighting

- Video game consoles

How To Minimize Blue Light Exposure

To reduce the effects of blue light on your sleep, here are some practical strategies:

1. Turn off screens before bed: Try to avoid using electronic devices at least two to three hours before bedtime. Reducing screen time helps prevent blue light from interfering with melatonin production.

2. Adjust your lighting: Dim your home’s lights or switch to warmer-toned lighting in the evening. You can also use lamps with red or orange light, which are less likely to impact your circadian rhythms.

3. Night mode settings: Many smartphones and computers have a "night mode" feature that reduces blue light emission. Make use of these features to limit exposure in the hours leading up to bedtime.

4. Blue light-blocking glasses: Special glasses designed to filter out blue light may be helpful for some individuals. These glasses can block or reduce the melatonin-suppressing effects of blue light.

5. Apps for blue light reduction: There are several smartphone and computer apps available that reduce blue light emission, allowing you to use your devices before bed without disturbing your sleep.

6. Create a sleep-friendly environment: If you can’t control light sources in your bedroom, consider using an eye mask to block out ambient light and promote better sleep.

The effects of heatwaves, air pollution, noise and overall climate change may extend beyond physical health. According to a new report by the Earth–Brain–Health Commission published in Nature Mental Health recently, they can have a significant impact on mood, cognitive function and overall psychological wellbeing.

The commission warns that environmental changes are altering the conditions in which people live. It also talks about consequences for brain health and mental wellbeing. It also calls for mental health to become a consideration in climate policy, urban planning and environmental decision making, rather than being treated only after symptoms develop.

The findings are relevant to low and middle-income countries, where exposure to environmental hazards can overlap with greater socioeconomic problems like poverty and limited access to healthcare.

“Heat and heatwaves, air and noise pollution, extreme weather and compound events, urbanization, and the loss of green and blue spaces are associated with depression, anxiety, cognitive decline, and impaired emotional and behavioral functioning,” the commission states.

Effects Of Environmental Conditions On Brain

Also read: Lancet Study Finds Air Pollution & Chemical Exposures Could Add To South Asia's Diabetes & Heart Disease Burden

From biological changes like neuroinflammation, disruption of hormones and the body's internal clock to psychological stress and due to isolation and displacement, the commission identifies several ways through which environmental conditions may impact mental health.

Heat exposure is one of the gravest concerns in current times. Heatwaves can disrupt sleep and contribute to physiological stress, while air pollution can lead to cognitive decline. Noise pollution and stressful urban environments may fuel anxiety and depression.

These exposures are compounded by people’s standard of living. A person living in poorly ventilated housing, for example, may face heat, air pollution, financial hardship and limited access to healthcare at the same time. These combined problems can be difficult to measure by studying each exposure separately.

Who Is At Risk?

Also read: Rising AQI In Delhi-NCR: Doctors Warn Of Lung And Heart Risks As Pollution Builds

Children, older adults, people with disabilities and marginalised communities may face greater exposure to environmental hazards while having fewer resources and help to cope with them.

The commission also highlights low and middle-income countries and small island developing states. These populations may face significant environmental risks but remain underrepresented in research on climate change and mental health.

Dr Vivek Benegal, senior professor of psychiatry and former head of department at the National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru, is among the commission's members. He said NIMHANS has been examining how climate change affects the human brain.

Benegal also pointed to a 2023 study conducted by researchers from NIMHANS and King's College London. The study found that even low levels of arsenic exposure, below World Health Organization thresholds, were associated with changes in brain structure and impaired cognitive abilities among children, adolescents and young adults.

Commission's Recommendations

The report recommends that governments should incorporate brain and mental health measures into environmental policies. Its recommendations include monitoring environmental exposures, identifying risks early in life, and designing healthier urban environments.

“The principal obstacles to action are organisational and financial rather than evidential,” the commission observes, noting that research cohorts, Earth-observation systems and environmental governance tools already exist but are often maintained separately.

COVID-19 vaccines were rolled out during the pandemic, so questions about their safety, how long they protect against infection and whether mRNA technology was tested for long enough continue to dominate public debate.

Dr Paul Offit, paediatrician and director of the Vaccine Education Center at Children’s Hospital of Philadelphia and former member of the CDC’s Advisory Committee on Immunization Practices, says many concerns overlook the the evidence collected before and after the vaccines were introduced.

In an interview with HealthandMe, Offit discussed how long COVID vaccine protection lasts, what scientists have learnt about rare side effects and why the technology behind mRNA vaccines was not as new as many people thought.

“I think it is probably the best studied vaccine in human history,” Offit said. He pointed to the large number of people who received them and the safety-monitoring systems used to look for adverse effects.

Why Are People Still Getting COVID After Vaccination?

Also read: EXCLUSIVE: Ex-CDC Vaccine Advisor Says Measles Outbreak Bigger Than Reported, Slams RFK Jr’s ‘No-See Evil’ Approach

The circulation of SARS-CoV-2, the virus that causes COVID-19, is sometimes used to argue that the vaccines do not work. Offit said this misunderstands the type of infection the virus causes and the protection vaccination offers.

“It’s a short incubation period mucosal infection,” he said. “So, vaccination or natural infection will protect you for about four to six months from mild to moderate disease, should protect you for longer against severe disease.”

He compared the future of COVID to influenza, saying that infections will continue even as vaccines help protect against serious illness.

“Even if everybody in the world were vaccinated every year, that virus would still circulate,” he said. “This virus is now with us forever.”

Offit said the goal of COVID vaccination is not necessarily to prevent every infection. It is to reduce the risk of hospitalisation and death, particularly among people most likely to develop severe disease.

“The goal of the vaccine is to keep you out of the hospital and to keep you from dying,” he said.

He said that people over 75, those with chronic heart or lung disease, pregnant women and people with weakened immune systems are at higher risk of developing severe complications from COVID. He said these groups should receive a vaccine every year.

Dr Paul Offit On COVID Vaccine’s Side Effects

Also read: American COVID Drives Cases And Deaths In UK: Unusual XFG Symptoms To Watch For

When COVID vaccines were first authorised in December 2020, the clinical trials involved approximately 35,000 participants across the Pfizer-BioNTech and Moderna studies, Offit said. Some rare side effects of the vaccine became apparent only after the vaccines were administered to much larger populations.

One such side effect was myocarditis, an inflammation of the heart muscle, and, less commonly, pericarditis, which affects the lining around the heart.

“Very quickly, it was found to be a rare cause, roughly 1 in 50,000 myocarditis,” Offit said, referring to mRNA COVID vaccines. He said cases were seen primarily in males aged 16 to 29 and were generally short-lived.

Current evidence confirms that myocarditis and pericarditis are rare but recognised risks associated with mRNA COVID vaccines. The risk has been observed most often in adolescent and young adult males, particularly within seven days after a second dose.

In June 2025, the US Food and Drug Administration required updated safety warnings for the Pfizer-BioNTech and Moderna vaccines. The FDA also noted that some patients in follow-up studies continued to show signs of heart muscle injury on MRI scans, with improvement in some cases. The long-term significance of these findings remains under investigation.

Offit also cited the example of Johnson & Johnson COVID vaccine, which was associated with a rare but serious condition involving blood clots and low platelet counts. The vaccine was no longer available in the US by May 2023.

“You're always looking and trying to find any rare side effect that's associated with the vaccine,” he said.

He added that concerns about stillbirths and pregnancy outcomes had circulated despite research examining vaccination during pregnancy.

Offit said there was “no evidence of congenital malformations, no evidence of premature birth or spontaneous abortion” in the studies he was referring to.

How Long Were mRNA COVID Vaccines Tested?

Another common concern is that mRNA COVID vaccines were developed too quickly and that the technology had not been studied for long enough. Offit disagreed, saying that the technology was not entirely new.

“I think it was studied for a long time,” he said. He pointed to research into mRNA as a vaccine platform that began decades before the COVID-19 pandemic.

“Drew Weissman and Katie Carrico met in 1997 and started working on mRNA as a vaccine platform, for which they won the 2023 Nobel Prize in Medicine,” Offit said.

He also referred to efforts to develop mRNA vaccines against SARS, the coronavirus that caused an outbreak in 2002 and 2003.

“But we really had, really since 1997, information about this vaccine, so like more than 20 years of studies of that vaccine,” he said. “People think it was a new vaccine, but it really wasn't that new.”

The technology had been studied before COVID-19, although the pandemic vaccines themselves still required clinical trials to establish their safety and effectiveness. After their introduction, researchers continued monitoring them to identify rare adverse events.

Do Benefits Of COVID Vaccines Still Outweigh The Risks?

Offit said the decision to vaccinate should take into account both the risk of side effects and the risk posed by COVID itself. “I'm an older person, so I'm going to get a COVID vaccine every year because I think that the benefits clearly outweigh the risks,” he said.

He argued that COVID continues to cause hospitalisations and deaths, making protection against severe disease an important consideration.

He said that the benefits outweigh the risks, particularly for people at higher risk of serious illness. Individual decisions should also take account of age, underlying health conditions, previous vaccination and current medical guidance.

One of the most common contributing factors in lung cancer is smoking but a recent report suggests an alarming pattern in which cases among non-smokers are on the rise.

Pope Leo XIV was recently diagnosed with lung adenocarcinoma, a type of aggressive cancer that develops in the cells lining the lungs. He had no history of smoking. The 71-year-old pontiff underwent surgery to have part of his right lung lobe removed. According to reports, he is out of the hospital and recovering well.

Another case is of Stanford physician Bryant Lin whose stubborn cough led him to seek medical attention. After six weeks, he underwent an X-ray. The diagnosis stated that he had stage 4 lung cancer. Lin was less than a month away from turning 50, and he had never smoked a cigarette in his entire life.

“Definitely a shock,” Lin recalled according to The Washington Post. By the time doctors identified the cancer in spring 2024, it had spread to his liver, bones and brain.

According to the US Centers for Disease Control and Prevention (CDC), around 10% to 20% of lung cancers in the United States are reported in people who have never smoked or have smoked fewer than 100 cigarettes in their lifetime. That amounts to an estimated 20,000 to 40,000 cases annually.

For these patients, their no-smoking history can delay diagnosis and treatment. Hence, researchers are now looking into how environmental exposures, genetic causes and the biology of tumours may contribute to lung cancer in non-smokers.

Lung Cancer In People Who Have Never Smoked

Also read: Pope Leo XIV, Diagnosed With Lung Cancer, Undergoes Surgery As His Brother Battles Relapsed Multiple Myeloma

Smoking remains the leading risk factor for lung cancer. But other reasons like exposure to radon, secondhand smoke, air pollution and asbestos can also increase risk. Family history plays a role, especially when a first-degree relative has cancer before age 50.

Researchers are also examining genetic differences that may help explain why some people develop lung cancer despite never smoking.

A study published in September identified a rare genetic mutation concentrated in the southeastern United States that was associated with a 60-fold higher risk of lung cancer among non-smokers. The finding focuses on a possible role for inherited susceptibility, but it does not explain most cases in this group.

Lung cancer also has a different demographic profile among people who have never smoked. Women who have never smoked are more than twice as likely as their male counterparts to develop lung cancer.

“Two-thirds of nonsmoking-related lung cancer happens in women, so there’s certainly an association with female sex,” said Jaclyn LoPiccolo, a medical oncologist at Dana-Farber Cancer Institute who co-authored the mutation study.

She added, “Nonsmoking-related lung cancer is also more common in people of East Asian descent, but whether that’s a genetic or environmental association, we don’t yet know.”

These Cancers Are Often Diagnosed Late

Also read: Pope Leo XIV Resumes Daily Activities After Lung Cancer Surgery: How Recovery Looks Like After Lung Lobe Removal

People who have never smoked may not recognise a persistent cough or other respiratory symptoms as signs of lung cancer. Doctors may initially consider more common explanations if the patient has no smoking history.

Never-smokers are often diagnosed late at more advanced stages of the disease because their doctors initially consider lung cancer to be less likely.

Haiying Cheng, a medical oncologist at Montefiore Einstein Medical Center in New York, said the stigma surrounding the disease can compound the problem. “A cancer diagnosis should never become a judgment about a patient,” Cheng said.

She added that clinicians need to consider assumptions beyond smoking when it comes to lung cancer and focus on the patient’s risk profile and tumour biology.

Lin is receiving antibody therapy targeting a cancer-driving mutation. He had a positive response to treatment.

“The treatment has done wonders for me,” he said. “When I was a medical student or resident, I would have never thought a Stage 4 lung cancer patient could be very productive and have a high quality of life almost two-and-a-half years after diagnosis.”

In the United States, the US Preventive Services Task Force recommends annual low-dose CT screening for adults aged 50 to 80 who have a smoking history. People who have never smoked are not included in these recommendations.

As researchers dig deeper into lung cancer chances in non-smokers, there is growing interest in different screening recommendations. Taiwan, for example, has a national early-detection programme offering low-dose CT scans to non-smokers with a family history of lung cancer.

Lin has urged his own sons to consider screening at a younger age. “I’ve got two sons, and I told them, ‘When you hit 45 or even 40, think about getting screened,’” he said.