We have arrived at a point in time when the generation known as Millennials, who first engaged with the internet as children, are mid-career professionals who treat internet-enabled technologies as extensions of their own hands. (Your humble correspondent first logged onto a whirring dial-up connection at the age of 11 and is now a 38-year-old dad who can’t keep his toddlers away from the family iPads.)

Technology is so integrated into our lives, especially our work lives, that we don’t spend much time thinking about what it may be doing to our health. If we’re being honest, we probably know using our devices may carry health implications, but we have no intention of changing our usage habits. So, we look away from the risks when we should spend more time looking away from the screens.

Guillermo Warley, a lecturer with the Institute for Learning in Retirement at Frederick Community College, draws on 40 years of experience as an electrical engineer to teach older adults about the social and health impacts of modern technology.

The good news is that, according to the best of his research on the subject, we don’t need to fear the electromagnetic signals constantly emitted by our devices.

He said institutions such as the World Health Organization, the National Cancer Institute, the Federal Communications Commission, and similar organizations in Europe, have concluded radio frequencies – signals we use for mobile phones, WiFi and Bluetooth – do not cause harm to the human body.

“X-rays are dangerous because they’re such high frequencies, their wavelengths are so tiny that they can disrupt things like DNA,” he explained. “That’s what’s called ionizing radiation, and that is dangerous. But the frequencies we use for radio transmission of any kind are orders of magnitude lower than that.”

The only possible source of direct harm from devices’ internal processes is the heat they generate, he said, but he hastened to add, “The human body has a very good capacity to dissipate heat, so you would have to have dramatic exposure for a very long time to even feel the heat.”

Warley has found a wide body of research showing negative impacts on eye health and sleep cycles from prolonged exposure to device screens, especially the common LED screens.

“They usually have a high component of blue light,” Warley said of LEDs. “It could have a good impact. For example, [blue light] has been used for treatment of concussions. But in those cases, it’s done with a controlled environment and a controlled dose, which really doesn’t resemble anything like what happens when people are constantly looking at the phone.”

Steven Allgaier, an optometrist with Walkersville Eyecare, said the pandemic lockdowns led to a new body of medical studies on the health effects of blue light exposure because isolation led Americans to spend more time looking at device screens.

Allgaier said about 20% of the population “seems to have a natural sensitivity to that spectrum of light. The blue end of the spectrum does have a higher energy wavelength, so there is potential to cause some issues.”

He said people who fall outside of that 20% do not appear to suffer noticeable symptoms from even prolonged exposure to the blue light emitted by LED screens. But for those within that population, symptoms can include headaches, migraines, and eye fatigue.

Additionally, he said, it’s possible for anyone, even those outside of the sensitive population, to have their sleep cycles disrupted by too much blue light exposure because it signals the body that it’s time to be awake even after the sun goes down. He said avoiding blue light in the hour before bedtime helps reduce these effects.

Warley said that blue light’s effect on the sleep cycle may be desirable in certain circumstances.

“It can keep you more alert, for example, but at the same time, that has some disruption for sleep,” he said. “It’s sort of like what happens when you drink a lot of coffee. It has some benefits if you want to be more awake, but too much of that and it starts to be a problem.”

There is a possibility that sensitive individuals may suffer retinal damage or macular degeneration from prolonged blue light exposure, Allgaier said, but “we don’t have enough information or longitudinal studies to know whether it’s actually going to matter or not.”

He believes a proactive stance is warranted in case long-term exposure eventually proves to have those severe effects. He said the good news is that simple steps can drastically reduce both the risks of serious damage and of the known fatigue and pain symptoms for sensitive groups.

He said the simplest way of limiting blue light exposure when an LED screen is necessary is to look at it from as great a distance as possible.

“The intensity of that [light] energy drops off exponentially as you get away from the screen,” Allgaier said. “For example, when you double the distance from 10 inches to 20 inches, you’re not just cutting the energy level in half, you’re cutting it four-fold.”

Similarly, turning down the devices screen brightness can drastically reduce that energy exposure, he said. Most devices default to their brightest setting but can be easily dimmed. He added that because tech companies are now aware of blue light hazards, most devices have blue light filters that can be activated in settings.

He said there are also glasses available that can filter blue light. “The thing that’s important to know about blue light [filtering] glasses is they still allow blue light through, but to a lesser extent,” Allgaier said. “The most common blue light glasses will filer anywhere from 15% to 20% of the blue light energy.”

Most lenses that filter a higher percentage of blue light are significantly yellow-tinted, he said, adding that a 15% or 20% exposure reduction is usually sufficient to abate symptoms.