Do Our Eyes Grow as We Age?

John Horton:

Hey there, and welcome to another Health Essentials Podcast. I'm John Horton, your host. When you think about growing up, you probably think about getting physically bigger, but one body part that doesn't exactly advertise how it sizes up are your eyes. They do grow, especially early in life, but we don't see dramatic and obvious differences year to year. But that begs a question: Just how much do your peepers change during your lifetime? We're going to focus on that question today with ophthalmologist Allison Babiuch. She's one of the many experts at Cleveland Clinic who join us weekly to help us better understand our bodies. So, with that in mind, let's get the long-term growth forecast for our eyes.

Welcome to the podcast, Dr. Babiuch. We appreciate you making some time for us.

Allison Babiuch, MD:

Thank you. I'm happy to be here to talk about eyes.

John Horton:

Well, and we're so glad you can stop by. And when it comes to our eyes, I think we all realize that they may change over time. My glasses can be exhibit A for that. But how much do the size and shape of our eyes vary over the years?

Allison Babiuch, MD:

They do. So I feel like a lot of people don't know this, but the eyes do actually grow as people get older. And especially babies. In those first few years of life, the eyes grow quite a bit. And then there's another growth spurt of the eyes in later childhood. And then the eyes continue to change even as adults.

John Horton:

Right. Well, we want to break all that down with you because there's a lot, I think, to go through there. So to make it easy, let's start at the beginning and work from there. How big are our eyes when we're born, and how quickly do they grow?

Allison Babiuch, MD:

Yeah, so there's a little variation between people, but most babies' eyes are about 16.5 millimeters, which is a little smaller than the diameter of a dime, so pretty small. And then within the first few years of life, the eyes grow quite a bit and they increase to about 22.5 millimeters in length. And then when the eyes are done growing, most adults' eyes are about 24.5 millimeters long.

John Horton:

Wow. All right. So there's a lot of growth that goes on. And it's funny because I know when you look at babies, I guess you don't really think about them growing because babies' eyes, a lot of times, they just look huge. Is that just an optical illusion because they're just such little people?

Allison Babiuch, MD:

No, it's true. So the eyes, even though they do grow, they do start off a little larger than the rest of their head. So the eyes do look big. The baby's eyes are about 65 to 75% of their adult size. The reason—

John Horton:

Nothing else is 65 to 75% adult size.

Allison Babiuch, MD:

No. So yes, the eyes do look big in babies, but the reason is because they need to start seeing for visual development and seeing and processing their world at a young age. So if the eye grew at the same rate as the rest of their head, they would be very blurry for a longer period of time when they're little and needing to see things.

John Horton:

So is that why, then, we see just such rapid growth early on? I mean, it's a process of getting them up to speed so they can see the world around them?

Allison Babiuch, MD:

Right. Yeah, because vision is so important for your development, and I'm sure it goes back to evolutionary for survival of we rely so much on our eyesight to process and function.

John Horton:

How much do babies see? I mean, I don't really remember, going back that far, but are they seeing things very clearly right away? Is it a couple months?

Allison Babiuch, MD:

No. So most babies are pretty blurry in the beginning and it's not till about 6 months or so of age that we expect babies to be able to see things across a room. So that's why parents, when they're right up close to their baby or a toy's right up front, they're smiling and reacting to it because they can see it better. And it takes a while when they get a little older that they can see things and those details farther away.

John Horton:

Yeah. Is that where you start seeing some of those developmental milestones where they start picking out mom and dad from across the room or something like that and you just see them light up and react a little more?

Allison Babiuch, MD:

Yes, exactly. And when we see kids in the office, even when they're, say, 3 years old, 4 years old, 5 years old, I don't expect kids to see perfect 20/20 vision at that age because their eyes still aren't done growing. So it's not normal for a young child to see perfect 20/20.

John Horton:

Wow. So they just keep adjusting and growing a little bit all through those early years?

Allison Babiuch, MD:

Yes. But again, there's these more rapid growth times. So within the first couple of years, the eyes grow quite a bit and then the eyes hit more of a growth spurt around, I'd say, 7 to 8 years old up until the early teenage years. That's where you see another big growth spurt.

John Horton:

OK. Now what's happening during that second growth spurt? Why is that one thrown in there?

Allison Babiuch, MD:

OK. So most kids, like babies, they are farsighted. Their eye is shorter than the average person's eyes, but the baby's eyes are so strong that they can focus and accommodate to be able to see clearly. And then when you get older and the eye grows more, it's going to become less farsighted. We call that process emmetropization. And in an ideal world, the eyes would just stop growing when it's the perfect size, but we know that that's not the case. A lot of people end up either being farsighted or nearsighted or having another reason to wear glasses.

So usually around 7 to 8 years old, the eyes will start crossing over to becoming nearsighted. So that's the eyes getting longer and then they're going to start having difficulty seeing far away. And that's when you're often seeing kids in elementary school, middle school starting to wear glasses and their prescription is getting worse and the prescription's getting stronger as they get older. And then the eyes stop growing sometime in the middle teenage years, usually around 15. But for some people, their eyes keep growing until the early 20s.

John Horton:

Now with all this growth that you're seeing then, it sounds like there's a sweet spot that it would be ideal if it just stopped. And I take it that's just where the lenses and everything come together and just everything is in clear focus. But it sounds like more often than not, we tend to maybe overshoot or undershoot that.

Allison Babiuch, MD:

Yeah. So in the US, the rate of nearsightedness is about 40%. So not most, but a lot of people end up becoming nearsighted and their eye isn't the perfect shape.

John Horton:

And all of that, and I think that's where it's so hard to understand. It's the shape and size of your eye that dictate whether you're nearsighted or farsighted.

Allison Babiuch, MD:

Right. So in order to see perfectly, it mainly has to do with the length of the eye. So the light comes inside of the eye or the image comes inside of the eye and then it should focus right on the back surface of the eye. We call that the retina. But if the eye is longer than the average person, then the focus point is going to be in front of the retina. And so the glasses are to shift that image back. And then if someone's farsighted, their eye is shorter than the average person, their image is focusing behind the eye. So they need glasses to shift that image forward to make it clearer for them.

There are other things that come into play, like the shape and size of their lens and the curvature of the front surface of the eye, the cornea.

John Horton:

But then it sounds like this all fits into that rapid growth that you see early on and then in those teen years, and it something gets you to that adult size by the time you're late teens.

Allison Babiuch, MD:

Exactly.

John Horton:

While our eyes do stop growing in adulthood, it sounds like they're not changing at all anymore. I mean, we still have a lot going on within these peepers, right?

Allison Babiuch, MD:

Yeah. So I wish that I could tell you that by the time your eyes are done growing that it's going to stay that way, but we all know that's not the case.

John Horton:

I wish you could too.

Allison Babiuch, MD:

Because most people in their 40s and 50s start needing reading glasses, and that's not because their eye is getting longer. It's because their eye is no longer able to focus because the eye muscles are tired because they're getting older, just like everything else. The lens that's inside of the eye, it has to focus to allow you to see up close. That's called accommodation. Kids' eyes are really strong. They can accommodate or focus very well, but as you hit your 40s to 50s, that ability to accommodate just goes down significantly, and that's why people start holding things farther away.

John Horton:

Yeah. My arms needed to get longer when I hit about mid-40s. Yeah.

Allison Babiuch, MD:

That's exactly right. So then you start needing reading glasses and you start off usually with a smaller amount, and then as you get older, the strength increases.

That's not the only change that happens as you get older. Other parts of the eyes start to sag also. They're just like people start getting wrinkly skin. The eyelids can start drooping. So I know a lot of older people notice that it's harder to see because their eyelids are drooping. And also the support structures around behind the eyes start to sag and degrade, and that's where the eyes start to look more sunken in. And sometimes even the support structures that hold the muscles in place that keep the eyes straight, they sag down and then people start getting double vision as they get older.

John Horton:

Yeah. The eyelids coming down, I know I have that, the awnings, and it runs in my family. We need a Dr. Zinzan for plastic surgery. He told me he could take care of that. I don't think I'm quite ready to yet.

Allison Babiuch, MD:

Yes, there are some surgical solutions for that. There are also some eye drops sometimes that help with that, but it is also just a natural part of aging.

John Horton:

Yeah. Now I also read where the lens in our eye becomes less flexible over time, and then that throws off our vision too.

Allison Babiuch, MD:

Yes. So there's a clear lens inside of the eye, and as you get older, the protein inside of the lens start to break down and clump up, and that makes that nice, clear lens cloudy or opaque, and that's called a cataract.

And pretty much everybody gets cataracts if you live long enough. So some people need cataracts removed slightly younger, in your middle age population, and some people as they get older, but that cataract does change the ability to focus and see clearly. Yeah.

John Horton:

And I also read, and this one really blew my mind, that our eyes get heavier as we get older too. I mean, is that adding to the extra numbers I'm seeing on the scale?

Allison Babiuch, MD:

Yeah. OK. They get slightly heavier, yes. And that's actually because of the cataract. So it's a little heavier than the clear lens. So yes, the eyeball itself is heavier.

John Horton:

I just want one thing to get lighter as time goes on. I feel like everything gets heavier, and knowing my eyeballs are even adding to that is really a little disappointing. I got to be honest.

Allison Babiuch, MD:

And I will tell you also that I feel bad for some adults because they'll get excited at their eye doctor's appointment because their amount of nearsightedness will get a little better. And you usually don't think about that happening, but it's actually the cataract that is changing their prescription. So they get this little reprieve for a couple years, but it also is a sign that like, ‘Oh, you're getting cataracts, and you're going to need cataract surgery someday.’

John Horton:

So it's just a little good news, but there's some bad news on the end of it.

Allison Babiuch, MD:

Yes, exactly.

John Horton:

Man, I really want to hear some of them ... I keep waiting for the guests to come in here to tell us that this aging thing is just absolutely fabulous and you gain a superpower, and it hasn't happened yet.

Allison Babiuch, MD:

OK. Well, OK. The one good thing is there are treatments for it, right? So if you get a cataract, there's a very simple surgical procedure where they take that cataract out and put a nice, clear lens in there, and sometimes that can make it so you don't need glasses anymore. So that's a positive.

John Horton:

All right. Well, look at that maybe in the future here. I'm a baby, though, when it comes to that sort of stuff, so I might be a little too squeamish for it.

So we've been talking, though, about eye growth throughout, and it sounds like when you hit adulthood then your eye isn't going to get bigger—your eyes aren't going to get bigger— but there's going to be changes within it. But pretty much that size they are by the time you hit in your 20s is about what you're going to have for the rest of your life?

Allison Babiuch, MD:

Correct, yes. So the length of the eye doesn't continue to grow past, say, mid-teenage or early 20s. So while other changes are happening inside of the eye, the eye is no longer growing longer. I guess how someone keeps growing taller until about the same age, same thing with the eyes.

John Horton:

OK. All right. And then basically everything sounds like everything within it starts getting a little more brittle, a little more rigid. Just like everything else that you hang onto for 50, 60, 70 years, it's not what it used to be.

Allison Babiuch, MD:

Yeah, that's true. Though I will say between your 20s to your 40s, it's usually a pretty good time for the eyes.

John Horton:

All right. Well, I can look back and remember the good old days.

Allison Babiuch, MD:

That's right. Your heyday. Yep.

John Horton:

So to wrap things up, Dr. Babiuch, what's the main thing you want people to understand about how their eyes grow and change over time and why that matters?

Allison Babiuch, MD:

So the eyes do grow, and there's a lot of changes that happen when kids are very young from infancy through their childhood. And these are all normal processes, but understanding that it often leads to needing glasses or contact lenses or someday maybe refractive correction, like surgery. But this is all normal growth of the eyes. But it is important for kids to be able to see clearly. So if kids can't see clearly, it's going to be harder for them to learn and process what's going on around them and especially learning in school.

So we do recommend that kids get their vision screened to check to make sure they don't need glasses. And if you have a family history of people needing glasses on the younger side, your kids are probably going to follow suit, and it's important to get them in and checked.

John Horton:

Yeah. How often should kids get those exams?

Allison Babiuch, MD:

So most states have vision screening programs in place. So the pediatricians, the family medicine doctors, the schools are screening the kids every year. So we really rely on that. And if your child is passing their vision screen and you're not seeing any problems, they're usually good. But as soon as they fail a vision screen, or you start to notice them trying to get up to the TV or whatever they're trying to look at and they say they're not seeing as well, then it's time to bring them in and figure out what's going on.

John Horton:

Yeah. And what about then into adulthood? How often should folks try to get in and just make sure everything is working like it should?

Allison Babiuch, MD:

Yeah, it totally varies per person, depending on what eye conditions run in their family and if they're needing glasses. Now, if someone is wearing glasses, they're going to have to come in every year or two as an adult to check for changes in their prescription and be looking at their eye health.

But for those lucky few who don't need to wear any glasses so they don't have to come in for that reason, it is still important to come in every once in a while. And I don't have a set time, but I would say maybe every 5 years or so just to check in and make sure that everything else is healthy and functioning well in the eyes.

John Horton:

And it sounds like, don't ignore those signs. I remember when I first got my glasses, and I went a good amount of time where you're squinting a little bit and looking at the board or whatever it is that's off in the distance, and then you realize, “Oh, I think I need a little help.”

Allison Babiuch, MD:

Yeah. And you have those moments where the parents and the kids didn't realize that their kid needed glasses maybe for a couple of years and then they get their first pair of glasses and it's like, “Wow, [inaudible 00:17:18] trees, and I can see the birds.” And it's sad, but it's also exciting for them.

John Horton:

Yeah. Well, it is. It is neat when you do it and it opens things up and then you realize it just keeps getting a little worse —

Allison Babiuch, MD:

It does.

John Horton:

And you just keep doing that same process over and over. So it's like an annual miracle for me at this point. So, Dr. Babiuch, thank you so much for walking us through the evolution of the eye. There's so many changes that go on in it, and it's amazing to me that this all just happens and we see or see with a little help, but there are these little subtle changes going on that we don't even realize.

Allison Babiuch, MD:

That's right. And the nice thing is that we have treatments and things to help us see better so that most people can see things clearly without having to live a blurry or defocused life.

John Horton:

Well, it seems like the clear point to end, so I appreciate you coming in and chatting and look forward to having you back.

Allison Babiuch, MD:

Of course. Thank you so much for having me.

John Horton:

When it comes to your eyes, they may stop growing early in life, but that doesn't mean they stop changing. So don't lose focus when it comes to watching your peepers to make sure they stay healthy. Thanks for joining us today. And if you liked what you heard, please hit the subscribe button and leave a comment to share your thoughts. Until next time, be well.

Speaker 3:

Thank you for listening to Health Essentials, brought to you by Cleveland Clinic and Cleveland Clinic Children's. To make sure you never miss an episode, subscribe wherever you get your podcasts or visit clevelandclinic.org/hepodcast. This podcast is for informational purposes only and is not intended to replace the advice of your own physician.