[Makda] We're in a galaxy of glasses.

[Makda] Shopping for spectacles.

There's choice galore.

[Makda] Our secret shopper is a Marketplace producer and she

really does wear glasses.

The frames are all about fashion,

but it's the lenses that are the real focus.

[Makda] We're taking a hard look at a filter that's supposed to

block the blue light from screens.

[Makda] Blue light-filtering lenses are everywhere online,

but we want to test how the country's big chains are

pitching the latest trend in-store,

so we're undercover inside Hakim Optical,

LensCrafters, Vogue Optical, and Hudson's Bay Optical.

We're visiting three stores for each of them.

That means a dozen visits.

[Makda] The sales pitch sounds and looks convincing.

[Makda] And then the claims start to sound alarming.

[Makda] At one chain, we even hear the "c" word.

[Makda] Yikes.

So what does it cost to save our eyes?

[Makda] And it seems to be popular.

[Makda] So should we all buy in?

To find out, we're off to Philadelphia to visit one of

North America's top eye specialists.

Along the way, we meet people spooked by the light from their

screens, too.

I think using the computer or the cell phone for a long time

can do harm.

It can have retina detachment by using it too much time.

I've heard that it's bad for you,

so I got my glasses with the blue light lens protecting so

that when I look at my computer screen or my cell phone,

I'm at work, whatever, that it doesn't damage my eyes.

If you look at screens too much, your brain and eyes

can get damaged.

Am I about to be duped?

[Makda] So we're off to America's oldest eye hospital,

established almost 200 years ago.

Today it's 15 floors devoted to everything eyeballs.

Look way up high.

[Makda] That's where Montreal-born

Dr Sunir Garg works.

Awesome.

Yeah, otherwise, your retina looks really great.

[Makda] He's an eye doctor and an eye surgeon.

Dr Garg is also a spokesperson for the American Academy

Of Ophthalmology.

We keep hearing the same thing about blue-light filter lenses.

Is this a new thing?

It's a new thing, and it's all over the internet.

I can't even open up, you know, any website without,

you know, "Hey, maybe you want to buy these blue light

"blocking lenses."

[Makda] Okay, then, let's hit play.

[Makda] We heard that several times.

Is blue light from your screens harmful?

No.

It's not.

And I don't know where that's come from and why it's taken off

so much, because it's not data driven.

I can't fault them, because I'm sure they're getting a little

info sheet that says you know what,

here's three talking points about blue light

blocking lenses.

[Makda] He understands why we'd buy into this.

I think people are thinking, Jeez,

you're right, after I use my computer for a bunch of hours,

my eyes don't feel very good.

I can't see really well, they're kind of irritated,

but what's bothering them isn't the blue light,

it's the fact that when they're staring at the screen a lot,

they're not blinking as often.

That causes the eye to dry out and when your eyes become dry,

they become irritated and scratchy and tired.

[Makda] There is a simple fix for that.

What you should do is just take a break and the American

Academy Of Ophthalmology has this 20-20-20 rule.

Every 20 minutes, take a 20 second break and look 20 feet

off into the distance, and that will break that near staring

that we tend to do when we're looking at the screen.

[Makda] But back on hidden camera,

we never hear that advice.

Yeah.

Tearing your eyes out would be really cool around Halloween,

but it's not something, you know,

that we see and I think people are exaggerating stuff.

Well, Jeez, I have these light rays that are little daggers

that are coming into my eyes and poking holes in my macula,

which is sorta what she's making it sound like.

She's saying "penetrating the eyes".

That sounds scary.

It does sound scary.

And if I'm trying to sell you something that you don't need,

maybe sounding scary helps to sell.

[Makda] Now on to claims of serious damage to the back of

the eyeball, Dr Garg's passion and specialty.

This whole orange area is called the retina.

The centre of the retina gets a special name.

It's called the macula and the macula is the part of the eye

that gives us our good reading and driving vision.

[Makda] In our hidden camera, the staff in stores also bring

up the retina and the macula.

[Makda] Unfortunately, she's just wrong.

And there's no evidence at all that blue light from the screen

is gonna cause macular degeneration.

[Makda] Blue light from our screens degrades our retina?

I don't have patients coming in ever with any signs of damage to

their retinas from looking at their screen all day.

Retinal damage, macular degeneration,

that sounds serious.

And it IS serious, but the blue light from your screen is not

the cause of that stuff.

And people should do things to protect themselves against

developing macular degeneration, but that's not buying

these glasses.

That's eating a proper diet, foods high in omega-3 fatty

acids, eating stuff like broccoli,

spinach, kale, three servings a week.

We know that helps.

[Makda] But we don't hear that in stores.

We hear about studies.

There are no studies that are showing that.

Nothing in people.

And so people will quote that.

Yes, blue light can hurt retinal cells,

but they're not telling you that's not been shown in a

person or any group of people using screens,

it's mostly in a petri dish or taking a poor mouse and holding

its head in a position and shining a blue light intensely

into their mouse eyeballs for hours on end.

That can also potentially be harmful,

but that's, again, not how it happens in people.

[Makda] The marketing in stores also sends the same messages

about the dangers of blue light from a screen.

And so do the company websites.

So everything that you have seen so far,

what stands out?

You know, I think people are exaggerating the problem and are

misleading their customers.

I think it's mostly benefiting the companies that are selling

these things, truthfully.

[Makda] We share our findings with the retailers.

They declined to come on camera, but they say the science is

still evolving and argue that blue light can be damaging.

Some say they'll reinforce their staff training and add that blue

light filter lenses won't harm consumers.

And the makers of those lenses?

They say people feel better using them and they

reduce eyestrain.

To get a second opinion about whether blue light from screens

is harmful, we head to Oxford, England,

to meet an optical radiation expert.

Professor John O'Hagan knows all about blue light.

Blue light in our normal environment is not dangerous

at all.

The main source of blue light for most people

will be from the sky.

[Makda] From the sky?

Really?

So how much blue light actually comes from our screens?

We ask him to measure that for us.

The light level coming from the phone is so low that we need to

turn down the lights in the room and bring the blinds down,

otherwise we're not going to measure very much.

[Makda] Professor O'Hagan fires up the spectro-radiometer.

[Professor O'Hagan] Levels are very low.

Very low output.

There is no evidence that the blue light from your mobile

device is harmful.

[Makda] Three years ago, Public Health England asked him to do

similar testing.

As part of our study, we looked at a whole range of different

phones, tablets, screens.

We didn't find anything that gave us cause for concern.

[Makda] He says we get around 30 times more blue light

from the sky.

O'Hagan's test determined the screens are harmless.

But that's not the message on hidden camera.

Remember this?

Cancer?

Yeah, no.

Those are the two most scary things you can talk about,

cancer and blindness, and you're telling me these glasses will

protect against both?

Where do I sign?

But that's just not where the scientific data is.

[Makda] Opticians at Hudson's Bay Optical are

the only ones who

mention a link to cancer, but they seem to be getting it from

this in-store pamphlet.

And the cancer claim shows up on Vogue Optical's website, too.

What did you think of everything that you saw?

These are big companies that are putting this information out

there, letting customers know that that blue light from your

screens is damaging.

I think that's a failing on their part.

You know, they should have the resources and the time and,

sort of, the pride in what they're selling to get good

information to their salespeople.

[Makda] Hudson's Bay Optical now says comments about cancer and

macular degeneration are wrong.

They say they'll pull those pamphlets and retrain staff.

And the maker of the lenses stands by its marketing.

Finally at a few stores, staff get this next claim right.

Blue light from ANY source can keep you awake.

There's an easy fix for that.

In the evening, turn on your device's night mode.

Your screens aren't going to make you blind.

I don't need to spend money on these things.

I should do things that will help my eyes which is to take a

break periodically when I'm doing things,

start quieting down before night time,

eat a good diet, exercise and not smoke.

Those things will help your eyes way more than spending money on

these blue-blocking lenses.