Can I just do this, please?

Jennifer Tsai: Yes. [laughs]

"Contact lenses can get lost behind your eye."

Uh, no.

"If you sneeze with your eyes open, they'll pop out."

I don't know where to start with this.

Um, myth.

Hi, my name is Dr. Rani Banik.

I'm a board-certified ophthalmologist

and neuro-ophthalmologist.

And I'm Dr. Jennifer Tsai,

practicing optometrist in New York City.

I specialize in medical and aesthetic eyecare.

And today, we will be debunking myths about vision.

"20/20 means you have perfect vision."

Ah, that's a good one.

A lot of people think 20/20 means perfect vision,

but there is so much to vision

beyond just reading the eye chart

and reading down to 20/20.

And when we say 20/20 vision, it means that this chart

is at 20 feet away from the patient

and they can read all the way down

to this line right here.

There are other lines below that.

Some people can actually read even better than 20/20.

But there are so many other components of vision.

For example, there's color vision,

there's peripheral vision, there's contrast.

Tsai: And we also check for near-point vision,

which has to do with reading up close.

And technically, you could have 20/20 vision

but have a condition such as glaucoma,

which can cause peripheral vision loss,

which means you have perfect 20/20 vision in the center

but you might have side vision loss.

"Blue light will damage my eyes."

Oh, my gosh.

I don't know what to think about that.

Back in 2018, there was a study that came out

that the media picked up on, and they said,

"Oh, blue light is going to damage your retina.

It's going to cause permanent blindness."

What the researchers did in this study was they took cells,

they put them in a petri dish,

and they exposed those cells

to high, high levels of blue light,

and they found out that those cells died.

The truth is that the cells that they put

in that petri dish were not even eye cells.

They were cervical cancer cells.

So, our retina cells have pigments

that protect us against blue light.

They're called lutein and zeaxanthin.

They're like our natural blue blockers,

and they protect our eyes against blue light.

So there is no proof that blue light damages your eyes.

And if it were really true,

we would actually have a pandemic of blindness

because all of us are on devices all the time,

children, adults, and it's just not true.

We do know that it affects our sleep

and it does cause insomnia

because it changes our circadian rhythm.

So when you wear a blue-light coating on your glasses,

it does help with light sensitivity and glare

and just generally making you feel more comfortable

when you're doing work.

So there is no downside to it.

The tint does make a difference,

because if you put on the lighter-tint blue blockers

and if you look at your screen,

if you can still see the color blue,

it means that that blue blocker's not blocking out

100% of the blue light.

Maybe it's blocking out a certain lower percentage,

maybe 30% to 40%,

versus if you put on these,

these are the super-duper blue blockers.

If you look at a screen Tsai: I love those.

with these on,

you don't see any blue whatsoever.

So, for example, if I'm having trouble sleeping

and I need to use my computer at night,

I'll wear these at nighttime, two hours before bed,

so it doesn't really interfere with my sleep.

The other thing that can happen

when you're on a screen for a long time

is probably you're not blinking enough,

so you're probably also getting dry eye,

and that's probably also contributing to the eye strain.

"You will lose your vision as you age."

I hear this all the time from my patients.

I have patients who are older,

your 60s, 70s, 80s, even 90-year-old patients

who still have 20/20 vision.

Tsai: Sometimes the dinner menu gets harder to read

at the restaurant, and I tell them that's absolutely normal.

That's not losing your vision.

It's just that our vision starts to change

in the other direction sometimes.

So, when we're referring to presbyopia,

that is the gradual change

when our eyes are not able to accommodate or focus

on near objects as well,

and we tend to hold things further back.

Banik: So, why does this happen?

Well, it's because inside the eye, we have a lens.

Now, normally the lens is very flexible,

and it can change shape.

Sometimes it can get thicker or thinner in the middle.

That allows us to focus at different distances.

As we get older, though,

this lens just doesn't change shape as well.

It becomes more stiff.

And when it becomes more stiff,

that is called loss of accommodation, or presbyopia.

And, again, that usually happens to most people

sometime in their 40s or 50s.

We also notice that over time,

our eyes start to improve as we get older.

It has to do with the fact that as we grow,

our eyes elongate,

and that can lead to myopia, or nearsightedness,

and over time,

just like our body can shrink,

our eyes can shrink shorter,

and that can lead our prescription to go the opposite way.

There's lots that can go wrong,

but as long as you see your eye doctor regularly,

you get checked for it, you get it taken care of,

you can still maintain good 20/20 vision

into your golden years.

"LASIK means no glasses forever."

I wish that were true,

but there is no guarantee with any kind of procedure

that your vision will be what you hope it to be.

Tsai: LASIK is just resetting your prescription

back to zero.

So LASIK can provide sharp, clear vision,

but that doesn't mean it can prevent myopia regression

or the need for reading glasses.

Sometimes there can be regression,

which means that after six months or a year,

the cornea may start to change back into its natural shape.

For the most part, it is very, very safe,

but just make sure you talk to your surgeon about it first

to make sure that you're a good candidate,

because not everyone is a good candidate.

OK. "Color blindness equals seeing in black and white."

This is an interesting one.

A lot of people think that if you have color blindness,

that's all you're going to see, is, like, monochrome,

but it's not true.

Most people who have color blindness,

or what we call color deficiency,

have issues with seeing different shades

of reds and greens and sometimes also oranges and yellows.

It's not that they can't see those colors,

they just see those colors differently.

So, we have cells in our retinas called photoreceptors.

The rods are responsible for light and dark vision.

The cones are responsible for color vision.

So we have red cones, green cones, and blue cones,

and these cones are all tuned in to certain wavelengths.

So in people who are color-blind,

it's not that they don't have those cones.

It's just that those cones are set

to a different wavelength.

So instead of seeing a red as bright red,

they may see it kind of as a muted color

or maybe as, like, an orange or yellow.

Actually, it's pretty common in the population

to have color blindness.