Name: 眼科医だけど質問ある？| Tech Support | WIRED Japan
Uploaded: 2025-01-14T09:30:03.000Z
Duration: 13 min 30 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Let's answer some questions from Twitter.

At Evan Murphy asks, how does LASIK eye surgery even work?

I perform LASIK and I even had LASIK done on myself.

What LASIK does is it helps to remove microscopic layers of tissue on the surface of the cornea to better direct the light as it enters the eye so that it's focused in your retina.

The biggest risk is risk of infection, although it's quite rare.

Less than one in 1,000 people would ever develop an infection.

At JJDGMN asks, what do eyeballs feel like?

I mean, the closest thing I can think that it feels like is a grape.

If you peel back a layer here, you can see how delicate this tissue is.

So if you were gonna squeeze an eye, it would kind of have the same squishy consistency of a grape.

It's filled with a jelly, which is called the vitreous, and then the tissue layers of the eye are really, really thin, almost like this thin outer layer of the grape.

When we're learning how to do surgery, sometimes we practice certain techniques on things like grapes.

At Junior Barnaby asks, how do ophthalmologists know babies need glasses?

One way we can tell that babies need glasses is their eyes are crossing, turning in, or turning out.

Another reason we can tell that babies can't see or might need glasses is if they're rubbing their eyes a lot.

Sometimes babies rub their eyes a ton because they're trying to stimulate vision.

Another reason is if babies are tilting their heads or if they're not fixating on objects.

Usually by about three months, babies should be able to see a toy or an object and kind of fixate on it and follow it if you move it around.

At Mark Swisher asks, what is the anatomical purpose of eyelashes?

Eyelashes actually exist to help trap all the dust, pollution, bacteria, allergens that exist in the environment so that they don't hit the surface of the eye.

It's actually proven that eyelashes should be a specific length.

If your eyelashes are too long, it's trapping too much of that in the environment and it can sit there and cause irritation on the eyes.

That's why it's so important to be washing over your closed eyelids every morning and evening to remove all that's been trapped in the eyelids and lashes.

At transreginal asks, my right eye twitches.

The most common is because of lack of sleep, too much caffeine or stress.

The muscles that are around the eye are very delicate and very sensitive to stressors.

At rdabdao asks, what are the dangers of wearing contact lenses while sleeping?

I have seen terrible damage to vision from people that sleep in their contact lenses.

Our eyes get their oxygen from the environment and when you wear your contact lenses for too long, you deprive the eyes of oxygen and that can leave you really prone to developing an infection.

And you can develop what's called a keratitis, which is an infection on the cornea, which is the surface layer of your eye.

Can lead to scarring and permanent damage to your vision.

At kevinclarknw asks, why does eyesight deteriorate with age?

Eyesight deteriorates with age mostly due to cataract.

The cataract is the clouding of the lens, which is on the inside of the eye.

This gets more yellow, big and thick as we grow up.

And that changes the prescription and also causes the vision to be blurry.

Cataract is actually the world's leading cause of blindness, but it's reversible with a surgery.

It's actually the most commonly performed surgery around the world.

I go inside the eye, remove the cloudy cataract and then put a new lens implant in its place that has your prescription in it.

It's an artificial lens, but it's really well tolerated.

It's biocompatible and can help to restore vision.

At keelnut wants to know, what does 2020 vision mean?

2020 vision refers to how we measure your vision on a vision chart.

So most vision charts are set for 20 feet away.

If you can see the 2020 line, that means that at 20 feet away from the eye chart, you can read that line.

And we refer to that as normal or perfect vision.

About 35% of the population can only see that 2020 line without glasses or contact lenses.

So say if you had 2050 vision, which would be this line here, what that refers to is that what you would be able to see at 20 feet being this line here, someone with perfect vision would be able to see at 50 feet away.

Some people can even have better than perfect vision.

So we would refer to that as 2015 vision.

If you were standing at 20 feet from the eye chart, the person with normal vision would only be able to see what you see if they stood closer at 15 feet to the eye chart.

At no amano thotties asks, what does legally blind even mean?

Like, can you get arrested for being blind?

So legally blind refers to vision that is 2,200 or worse. 2,200 is this big E on the chart.

If you're standing 20 feet away from the vision chart, this is the only letter that you can read.

While somebody with perfect vision would be able to stand 200 feet away and also be able to read this E.

At nullsy27 asks, do carrots actually improve your eyesight or have my parents been lying to me my whole life?

They have beta carotene, which is an important part of the vitamin A pathway.

There's actually big studies that we've done that look at nutrients and how they affect your vision.

The main nutrients that are recommended are vitamin A, vitamin C, vitamin E, lutein, and zeaxanthin.

These vitamins that are recommended are really important in the metabolic pathway of the cells that are in your retina, which is that vision sensory organ of the inside of the eye.

At axiehus wants to know, how do people know they're colorblind?

You might know it's not right because you'll start to sense that there aren't as many differences in colors.

Most people who are colorblind, it's not that they can't see color, it's that colors are much more muted.

These are what are called Ishihara color plates.

So if you're colorblind, you might not see this red number six in the sea of green.

Similar to this one, you might not be able to see the green S in the sea of red.

The most rare form of colorblindness is blue colorblindness.

So you might not be able to see the 10 here in the sea of blue.

At farabee14 wants to know, seriously though, where do eye floaters come from?

Eye floaters are a natural part of the eye's anatomy.

Your eye is filled with a jelly, it's called the vitreous.

This jelly starts to liquefy as we grow up.

When it liquefies, you get clumps of cells and collagen, which are in this jelly that clump together and then cast a shadow on the retina.

So the floater that you're seeing moving around is just kind of a clump of cells in this now liquefied vitreous jelly, casting a shadow in the back of your eye.

At msclare18 asks, where do these tears come from?

It's a gland that is in the upper outer corner of your eyelid.

The purpose of tears is to help keep your eyes lubricated.

Our eyes need to be lubricated for us to see clearly through.

That's why people that have dry eye feel like their vision is blurry and their eyes feel really uncomfortable.

At megstand asks, I hate having to get my pupils dilated at the eye doctor.

What is the purpose of that other than giving me a migraine?

The reason we need to dilate your eyes is to take a look inside the back of your eye.

As you can tell, the pupil, it's really hard to see through it if it's small.

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眼科医だけど質問ある？| Tech Support | WIRED Japan

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