Most of us spend a lot of time in front of devices, be it laptops, computers, or TVs and smartphones. In fact, according to a report by app analytics firm App Annie, in 2021 Indians spent an average of 4.7 hours a day on cell phones, compared to 3.7 hours in 2019. Notably, the pandemic of Covid had a huge role to play here. It is a known fact that excessive screen time has a detrimental impact on the eyes. However, the blue light emanating from it is also harmful to other aspects of health.
Blue light, which is part of the visible light spectrum that humans can see, “has the shortest wavelengths and therefore the highest energy,” says Dr. Sudipto Pakrasi, chairman – ophthalmology at the Medanta Hospital. Although natural and a part of sunlight, it is also emitted by various gadgets such as TVs, laptops, smartphones, tablets, gaming devices, etc., which are the artificial sources of blue light .
“Blue light emitted by electronic devices has been linked to a host of eye problems such as cataracts, macular degeneration, dry eyes, blurred vision and eye strain,” says Dr. Rishi Bhardwaj, HOD – Ophthalmology, Paras Hospitals, Gurugram.
“Prolonged exposure also has a cumulative effect and aggravates eyestrain and myopia,” says Dr Shailja Tibrewal of Dr Shroff’s Charity Eye Hospital in New Delhi. “Blue light can aggravate dry eyes and accelerate age-related macular degeneration (AMD). This could lead to loss of vision in the eyes. What is concerning is that while harmful UV rays are emitted by the sun, blue light is emitted both by the sun and by light-emitting gadgets and LEDs,” she adds.
When it comes to retinal and macular degeneration, Dr. Pakrasi says blue light toxicity can lead to this, but the genetically predisposed are more at risk. Explaining the eye disease, the doctor says macular degeneration causes vision loss in the center of the field of vision. “Dry macular degeneration deteriorates the center of the retina, while wet macular degeneration causes leaky blood vessels to grow under the retina, leading to blurred vision and permanent eye damage,” he adds. Apart from that, we tend to blink less often in front of a screen, which adds to the ailments.
According to Dr. Bhardwaj, children may be at greater risk of blue light damaging their eyes because it is not filtered out as well by a child’s eyes as it is by adults.
“During the Covid pandemic, due to overexposure to digital devices, children have complained of several eye problems such as dry eyes, watery eyes, progression of myopia, pain in the eyes, as well as a loss of circadian rhythm and a disturbed sleep pattern,” says Dr Tibrewal. , adding: “Apart from children, anyone who uses digital devices for 4-5 hours a day is at risk. Moreover, their effects are additive, which means that over time they will only add and increase and can cause photochemical damage, the generation of free radicals in the retina, and disturbed and damaged vision. The earlier a person is exposed to excessive blue light, the greater the damage later in life.
Do you know that late night screens disturb your sleep? “Not only the eyes, but blue light also causes many sleep dysfunctions,” says Dr. Pakrasi, adding, “It does this by slowing the release of the hormone melatonin, which is responsible for sleep, thereby affecting sleep, causing eyestrain, tiredness. , headaches, sleep deprivation, confusion, etc.
“Studies report a negative association between exposure to blue light at night and subjective quality of sleep,” says Dr. Jitender Jakhar, Consultant Psychiatrist, Fortis Hospital, Vasant Kunj, New Delhi.
It should be noted here that any light can disrupt sleep by suppressing melatonin secretion, but the damage is greater in the case of blue light. A group of Havard researchers compared the effects of 6.5 hours of exposure to blue light versus green light of comparable brightness. They found that blue light suppressed melatonin about twice as long as green light, thus affecting sleep more.
“Sleep and mental health share a two-way relationship,” says Dr. Jakhar. Primarily, by influencing the sleep cycle, blue light can indirectly predispose an individual to emotional distress. Therefore, sleep disturbances may be a prodrome symptom of mental illness,” he says. “Prolonged exposure can also increase the level of cortisol, the stress hormone, and make an individual more irritable and anxious,” he adds.
The harmful impact of overexposure to blue light does not stop there. As it affects sleep, causing sleep deprivation, confusion, fatigue and headaches, the aggravation of which can also contribute to the onset of other conditions such as high blood pressure, diabetes, psychotic problems and have a significant link with depression and mental health problems; and in severe cases, it has been linked to cancers such as prostate, colorectal and breast cancer, says Dr. Pakrasi. In children, it can also “raise their risk of obesity and attention deficit disorder,” says Dr. Bhardwaj.
Speaking about the risk of cancers, Dr. Jakhar explains: “Exposure to blue light at night and circadian rhythm disorders are associated with an increased risk of hormone-dependent cancers. The risk of prostate and breast cancer is positively correlated with exposure to the spectrum enriched with blue light. Few studies have reported that exposure to artificial blue light increases the risk of prostate cancer by 1.5 times.
It does not stop there but also accelerates the natural aging process as continued exposure to light emitted by these devices increases oxidative stress in the body and initiates biochemical changes in cells resulting in the production of an intermediate reactive oxygen, which leads to necrosis and apoptosis, which are the cardinal causes of aging, explains the doctor.
Interestingly, daytime exposure to blue light has health benefits because it “boosts alertness, memory, and brain function, and improves mood,” the doctors say. “It regulates the body’s natural sleep-wake cycle, or circadian rhythm. Exposure to blue light during the day helps maintain a healthy circadian rhythm,” says Dr. Pakrasi. However, much of it revolves around sunlight, and even light emitted by gadgets at night can have the opposite effect.
“We advise people to use their devices as little as possible,” says Dr Tibrewal. “Schedules may differ between children and adults. For example, for children, we recommend a maximum of 2 hours on gadgets,” she recommends.
Here’s what doctors recommendFor kids
- Limit device usage
- Tell them to put away any portable gaming device at least 30 minutes before bedtime
- Turn on blue light filters from electronic devices. Many laptops and smartphones come with blue light filters in their software that change the color of the screen to yellow, which soothes the eyes and prevents blue light-induced damage.
- Use blue-blocking glasses or an app that filters blue/green wavelengths if you work nights or spend a lot of time using gadgets at night
- Take a 15-20 minute break after each task if your job requires excessive screen time
- Follow the 20-20-20 rule in which you focus on an object 20 feet away for 20 seconds after working on a screen every 20 minutes
- Blink frequently to avoid dry eyes