SCREEN SAVIOUR

Are blue-light-blocking glasses just hype? Dr. Kirsten North, an Ottawa-based optometrist and consultant for the Canadian Association of Optometrists, breaks it down.

What is blue light, and how does it affect our eyes? “Blue light is part of the light that we see. It’s the part that has the shortest wavelength. Because it has a short wavelength, it has a lot of energy. It’s that energy that can cause damage to our eyes.”

In what way can it cause damage? “It has been linked to an earlier onset of cataracts, possible macular degeneration and eye strain.”

Is that referring to blue light from

devices or blue light from the sun? “Both. But what we have done in recent years is really ramp up our blue-light exposure by being on devices and changing all our lighting to LED, which has a higher percentage of blue light.”

Is the blue light from devices different

from, or more dangerous

than, the blue light from the sun? “The jury is still out on that one. You definitely get more blue light from the sun, but it’s farther away. You’re getting less blue light from a screen, but it’s closer.” Are glasses with blue-light protection something you recommend? “It depends on the filter, because there are two kinds of blue light: blue-violet and blue-turquoise. Some companies filter just the damaging blue-violet rays, which has no effect on your sleep cycle. The filters that you can put on your phone are looking at blue-turquoise light [which affects circadian rhythm]. So it’s not a onesolution problem. If a company were to make a blue-light filter that blocks both, you’d be sleepy all day long.” Would wearing blue-light glasses

help with the headaches one might

get from looking at a computer screen all day? “It might. Blue light and staring at the computer have definitely been linked to eye strain, but there are other things that can cause headaches and eye strain as well. I would recommend a complete eye exam to look for focusing issues or poor ocular alignment, meaning the muscles have to realign the eyes constantly, all day long.”