How Blue Light Exposure Impacts Vision

Blue light is back in the headlines thanks to new discoveries about the short-wave light. Previously, scientists were concerned about the effects blue light could have on sleep. Studies now suggest there may be more at risk — especially for kids — than previously thought. 

Understanding Blue Light

Visible light comes in a full rainbow of colors, from red to violet. On that spectrum, each color has its own energy and wavelength. On one end, there’s red light, with longer wavelengths and lower energy levels. At the other end, there’s blue light with shorter wavelengths and more energy.

While no one light is all good or all bad — there are pros and cons to most colors of light on the spectrum, including blue light — overexposure, or exposure to the wrong light at the wrong time, can have lasting effects on health.

Human exposure to blue light comes from a variety of sources. Due to the overuse of devices that emanate blue light, like smartphones and tablets, we’re getting more exposure than ever before. 

Dr. Robert Weinstock, of the Eyesafe Vision Health Advisory Board tells Parentology children’s eyes are especially vulnerable due to a lack of natural filtration. Kids’ lenses are still transparent and clear, unlike adult eyes that become hazier and thicker as cataracts naturally develop over time. Additionally, children and teens may be at risk of overexposure because of how closely they hold phones and tablets to their faces during use. 

Signs and Effects of Exposure

Overexposure to blue light rays doesn’t show up immediately. Much like how too much exposure to the sun’s UV rays appears in sunburn, blue light impact reveals itself in more subtle ways. You may notice your child having trouble falling asleep, or staying asleep, due to blue light’s impact on natural circadian rhythms. “Before bed, we need to have a natural decrease in light exposure to stimulate melatonin in the brain,” Weinstock explains. “This is important for neurotransmitters in the brain.”

He adds, “When a child is exposed to phones and tables for a long period of time, especially at night, it’s unnaturally exposing them to blue light.Therefore, it’s suppressing melatonin production and preventing the child from sleeping well.”

For kids, a bad night of sleep can result in poor concentration, agitation, irritability, and difficulties in school. “Interfering with the wake and sleep cycle of the circadian rhythm is a significant problem with children exposed to blue light on devices.”

Not to mention, too much exposure to blue light can lead to retinal problems down the road.

Taking Charge of Blue Light

These days, many cell phones and tablets have blue light filters already built-in. Beyond this, there are well-established and scientifically proven products on the market designed to limit exposure. Another step Weinstock suggests: limiting screen time closer to bedtime.

Blue Light Exposure Sources:

The British Medical Journal
Dr. Robert Weinstock