Blue light a special problem for eye

The growing prevalence of digital devices comes with plenty of benefits. But, as with most things, the benefits come with some drawbacks.

And for those working in optics, one drawback that’s gaining more and more attention is the light emitted from smartphones, laptops and tablets and the impact all of those hours of exposure are having on eye health.

“I’ve really seen this go from a really fringe topic to a mainstream topic,” said Alan Burt, senior product manager for VSP Optics Group, who has been working in optics for the last 10 years.

“The way that we light and see the world has changed in a way that’s unprecedented,” he said.

In the last 10 years, there’s been a shift to energy-efficient lights, making the use of LED lighting more commonplace. During that time, backlit devices — such as smartphones, laptops and tablets — have also become mainstream, Burt said.

“What we’re beginning to understand is there are some pretty serious considerations to vision and health,” he said.

That’s because LED lights, TVs, computers, smartphones and tablets all emit something called blue light.

The visible light spectrum has a range of energy people can see with their eyes. Think of the whole light spectrum as the acronym used for rainbows, ROYGBIV: red, orange, yellow, green, blue, indigo and violet.

The highest energy portion of the visible light spectrum — located right next to ultraviolet, or UV — is blue light.

“It sits right next to UV, and we know the damage UV causes,” Burt said.

Other forms of artificial light, such as candles, fire and even incandescent bulbs, fall in the red, orange and yellow portions of the light spectrum, Burt said. LEDs, however, put out more and higher energy — blue light.

“The quantity has increased, as has the intensity,” Burt said. “All energy has a consequence.”

And those working in optics have several concerns about the increased exposure to blue light.

Visual strain, fatigue

The first concern is how blue contributes to visual strain and fatigue.

“The reason for that is just the way your eyes and brain process blue light,” Burt said.

The eye lens — the front part of the eye — defocuses the blue light before it reaches the retina, which is in the back of the eye. People perceive that as glare, Burt said. That’s why the blue headlights on vehicles often appear glaring, he said.

“Our eyes don’t process that blue light as well,” Burt said. “It scatters, and we perceive it as glare.”

People sitting in front of a computer screen for eight hours perceive the blue light as a low, rolling glare, Burt said. By the end of the day, their eyes feel tired from working overtime to process the blue light.

That, Burt said, can lead to visual strain and fatigue.

Disrupting sleep

Another concern is how blue light is affecting sleep patterns. Research has shown blue light interferes with a person’s production of melatonin — a hormone that helps control a person’s sleep and wake cycles — and using devices before bedtime can interrupt those natural rhythms.

“All that blue light from artificial sources is tricking our eyes into telling our brain it’s not nighttime yet,” Burt said. “It’s important that you’re exposed to it at the right times of day, and being exposed to a high amount at nighttime isn’t a good thing.”

Macular health

One of the biggest concerns surrounding blue light, at least for Dr. Shawn Brittain, an optometrist at Westside Eye Center in Hazel Dell, is its contribution to the rise in macular degeneration cases.

“These last 20 years, there’s been this huge ramp-up in macular degeneration,” he said. Many things are likely playing a role — the increase in health issues like diabetes, genetics and smoking — but research is beginning to point to blue light as a factor, as well, Brittain said.

“Blue light, we’re finding, is a definitely culprit of it,” he said.

The macular is the center part of one’s vision. Macular degeneration is essentially the oxidizing, or rusting, of the center of one’s vision, leaving the person blind.

“What we’re finding that speeds up this rusting, or oxidizing, is blue light,” Brittain said.

As a person ages, their eyes naturally produce a pigment in the lenses that protects against oxidation. Babies and young children, however, have no protection from blue light, Brittain said. Making the growing use of blue light-emitting devices by toddlers and young kids particularly troubling, he said.

Protecting eyes

While the possible impacts of blue light on one’s vision can be troubling, Burt and Brittain said there are ways people can mitigate those impacts — and they don’t require swearing off digital devices.

A coating can now be applied to eyeglasses, both prescription and nonprescription, that restricts some of the blue light reaching the eyes, Burt said. VSP created such a product called Sharper Image Tech Shield.

In addition, filters are available for computer, tablet and cellphone screens. Brittain uses slip-on filters that reduce blue light emitted from his computer screens by 40 percent to 50 percent. The filters for smartphones and tablets are applied to the devices like screen protectors.

Another factor is how close the device is to the person’s face, Burt said. Watching a TV that’s sitting 20 feet away makes less of an impact than a person holding a tablet 8 inches from their face, he said.

And when sitting in front of a computer screen or using other devices, Burt recommends following the 20-20-20 rule.

“Every 20 minutes, take a break from your screen for 20 seconds and look 20 feet away,” he said. “That’s a practical thing everybody can do.”

Burt and Brittain also recommend regular appointments with providers, who can monitor eye health and offer recommendations based on individual habits and exposure to blue light.

“We’re still trying to get a handle on blue light,” Brittain said.

“We don’t have a full picture yet, but it’s looking like it’s a lot bigger deal than we ever thought,” he added.