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  • Thanks to Simple Contacts for supporting this episode.

  • Go to simplecontacts.com/scishow and use the promo codeSciShowto get twenty dollars

  • off your next order of contacts.

  • [ INTRO ]

  • If you don't have perfect vision, you've probably had your fair share of eye exams.

  • They sit you down, ask you if things look better with option oneor two

  • and also blow that puff of air in your eye to test for disease.

  • If you're one of the lucky ones with no vision problems, though, getting your eyes

  • checked on a yearly basis probably isn't your top priority.

  • I mean, you can see just fine, so why go?

  • Well, visiting an ophthalmologist is about more than just checking your visionit's

  • also good for your overall health.

  • All kinds of conditions can show up in your eyes, sometimes before they're obvious anywhere

  • else.

  • They include everything from STIs to cancerbut since we can't cover them all, here

  • are four of the more common ones.

  • your eyes are so useful for detecting health conditions because they're packed with different

  • kinds of tissues and cells.

  • There are blood vessels, nerve cells, muscle cells, and more,

  • which means the eyes are susceptible to diseases that affect any of those things.

  • On top of that, it's really easy to see inside the eye, since the outer covering is

  • transparent

  • or see-through if you will.

  • It's the only organ where doctors can see your blood vessels without any serious obstructions.

  • With the right equipment, they can even see red blood cells moving through your capillaries!

  • So the eye is the perfect looking glass into your body's overall health.

  • Some of the things a doctor can learn from your eyeballs are pretty straightforward.

  • For example, one of the easiest things for them to spot is if you have high blood pressure,

  • otherwise known as hypertension.

  • High blood pressure can develop over many years, but unless you regularly get checked

  • for it, it can be hard to detect.

  • The physical symptoms are often elusive, but can sometimes manifest as really bad headaches,

  • chest pain, trouble breathing, or dizziness.

  • And if left untreated, hypertension can cause strokes or heart attacks, or can even lead

  • to dementia.

  • A general practitioner can usually catch high blood pressure during a regular checkup.

  • But eye doctors can also notice it, because hypertension leads to some significant changes

  • in blood vessels.

  • Although researchers aren't sure why, it causes the blood vessels to resist and push

  • against the blood flowing through them, which causes pressure to rise.

  • Over time, that leads to the vessels becoming narrower and stiffer.

  • And while this happens all over the body, it can be easily seen in the retina, which

  • is near the center of your eye.

  • The narrower the blood vessels get, the harder it is for blood to flow into the retina.

  • That makes the pressure go up in the eyeball and causes it to become swollen, which can

  • lead to blurry vision or seeing white spots.

  • More severe hypertension can also cause hemorrhages and leaking in the eye because the blood vessels

  • get weak and burst,

  • but that can also be easily noticed during routine eye exams.

  • Another commonly-spotted problem in the eyes is high cholesterol.

  • Cholesterol is a waxy substance that builds up in blood vessels over time,

  • and it makes it harder for blood to get where it needs to golike the heart or the brain.

  • You know, important places.

  • If a piece of it breaks off, it can also get stuck somewhere and cause a heart attack or

  • stroke.

  • Like with high blood pressure, a general practitioner can tell you about your cholesterol levels

  • but again, so can an ophthalmologist.

  • If there's too much cholesterol in the eyes' blood vessels, it can cause something called

  • retinal vein occlusion.

  • This is where a clot cuts off the blood supply to part of the eye, and it can cause blurry

  • vision, or even vision loss if it's severe enough.

  • It is worth noting that this occlusion can also be caused by high blood pressure or diabetes,

  • but regardless,

  • it's a sign that something isn't quite right in the body.

  • Speaking of diabetes, though, that's another condition that's sometimes first spotted

  • in the eye.

  • Diabetes affects more than 420 million people worldwide, and it's actually a major cause

  • of blindness.

  • The disease has plenty of signs and symptoms, like being really tired, thirsty, or hungry,

  • but one big one is blurred vision.

  • This can be caused by retinal vein occlusion, but it can also happen because of diabetic

  • retinopathy.

  • This is damage that happens to blood vessels when too much sugar builds up in the body.

  • In particular, sugar damages the blood vessels that feed the retina.

  • When these vessels are damaged, they can bleed or leak fluid, making your vision fuzzy.

  • The leaking can also cause the center of the retina to swell, which further contributes

  • to the blurriness.

  • At this point, scientists aren't exactly sure why sugar build-up damages blood vessels,

  • but it definitely can.

  • And if you don't treat diabetic retinopathy, it can eventually lead to blindness.

  • So while there are other ways to detect diabetes, sometimes, these vision problems are someone's

  • first red flag.

  • Finally, many inflammatory diseaseslike Crohn's disease and lupuscan also be

  • detected in the eye.

  • Inflammation is totally normal, and is our body's response to an injury or infection.

  • When you get hurt or sick, your body dispatches white blood cells, and they work to attack

  • and get rid of the invader.

  • With inflammatory diseases, though, there isn't an injury

  • but the body responds as if there were one.

  • These conditions are less common than something like hypertension or diabetes,

  • but they still affect more than a million people, and that number is growing.

  • Inflammatory conditions can be caused by a number of things, from infections to autoimmune

  • disorders,

  • but ultimately, they lead to prolonged inflammation in the body.

  • And that can cause something called uveitis, which is typically when the middle part of

  • the eye, called the uvea, swells.

  • It happens when inflammatory cells flood the eye, and it can cause blurred vision, light

  • sensitivity, or dark floating spots, among other things.

  • And if you don't treat it, it can lead to permanent eye damage.

  • These examples are just the tip of the iceberg when it comes to conditions that affect your

  • eyes.

  • So while the saying might bethe eyes are the windows to our souls,”

  • it turns out they're more like the windows to our health.

  • While you definitely need to get your eyes examined,

  • you can now test your vision and renew your contacts without heading to the doctor's

  • office thanks to Simple Contacts.

  • They allow you to renew your contact lens prescription and order your brand of contacts

  • from anywhere,

  • and it only takes a few minutes.

  • They worked with ophthalmologists and doctors to design a self-guided vision test you can

  • do at home to check your vision prescription.

  • And while it definitely isn't a replacement for a full eye health exam, it can help you

  • confirm that your current prescription is helping you see twenty-twenty.

  • If you want to learn more, you can head over to simplecontacts.com/scishow.

  • And if you use the promo codeSciShow”,

  • you'll get twenty dollars off your next order of contacts.

  • [ OUTRO ]

Thanks to Simple Contacts for supporting this episode.

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B1 INT blood vision eye hypertension high blood diabetes

4 Big Reasons to Get Your Eyes Checked (Even With 20/20 Vision)

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    林宜悉 posted on 2020/03/30
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