A Doctor-Approved Guide to the Sun This Summer

Summary

Podcast Summary: Chasing Life – A Doctor-Approved Guide to the Sun This Summer

Episode: A Doctor-Approved Guide to the Sun This Summer
Host: Dr. Sanjay Gupta
Release Date: July 1, 2025

Dr. Sanjay Gupta delves into the nuances of sun exposure during the summer months, addressing listeners' concerns about balancing the benefits of sunlight with the risks associated with overexposure. This episode provides expert insights on eye health, effective sunscreen usage, and sun safety practices to ensure a healthy and enjoyable summer.

---

Understanding Sunlight Exposure for Eye Health

Listener Question:
Deirdre from Philadelphia raises an important concern regarding sunlight exposure to the eyes. She shares conflicting advice received—from a friend’s physician recommending unfiltered sunlight for the eyes to her own eye doctor advising constant use of sunglasses. Her question: “What’s the truth about getting 10 minutes of sunlight on your skin without sunscreen?” (00:43)

Expert Insight: Dr. Raj Muturi, Ophthalmologist
To address this, Dr. Gupta consults Dr. Raj Muturi, a seasoned ophthalmologist and spokesperson for the American Academy of Ophthalmology. Dr. Muturi provides clarity on optimal sunlight exposure:

• Morning Sunlight Benefits:
  “Aim for 10 to 15 minutes of direct unfiltered morning light. No windows, no sunglasses. As soon as practical after waking up,” advises Dr. Muturi (03:21). He emphasizes the importance of exposure within the first 45 minutes after sunrise to safely obtain vitamin D without the risks associated with higher UV levels later in the day.

• Circadian Rhythm and Mood Enhancement:
  Morning sunlight helps reset the circadian rhythm, boosting mood and improving sleep patterns, while also playing a role in preventing nearsightedness, especially in children. Dr. Muturi explains that bright outdoor light triggers dopamine release in the retina, which inhibits the elongation of the eyeball—a key factor in myopia development (04:42).

• Risks of Midday Sun Exposure:
  Dr. Muturi cautions against prolonged midday sun exposure, particularly between 10 AM and 4 PM, when UV radiation peaks. “Midday sun can cause photokeratitis and increase the risk of macular degeneration,” he warns (05:22). Prolonged exposure without protection can lead to both short-term discomfort and long-term eye health issues.

• Fireworks Safety Reminder:
  With the July 4th celebrations in full swing, Dr. Muturi emphasizes the importance of wearing safety glasses around fireworks to prevent ocular injuries. “Everybody wants to use them, especially kids. 90% of it is towards men. So the men out there, be super careful. Please don't be that statistic,” he urges (07:23).

---

Protecting Your Skin: Choosing and Using Sunscreen

Listener Question:
Inspired by Deirdre’s inquiry, Kira Daring probes deeper into sunscreen usage: “What kind should we be using? You know, what SPF level or how much is actually enough to protect us?” (10:30)

Expert Insights:

1. Types of Sunscreen: Physical vs. Chemical
   Dr. Rachel Neal, an epidemiologist, breaks down the differences:

   • Physical (Mineral) Sunscreens:
     “They sit on top of the skin and form a barrier,” explained Dr. Neal (11:25).
   • Chemical Sunscreens:
     “They bind to the top surface of the skin and turn the UV radiation into heat,” adds Dr. Neal (11:25).

   Dr. Neal prefers chemical sunscreens for daily use due to their lighter texture and lack of a white veil, despite physical sunscreens offering a tangible barrier against UV rays.

2. Application and Usage Guidelines:
   Dr. Laura Vandenberg, a public health scientist, emphasizes the importance of proper sunscreen application:

   • Amount:
     “Three full fingers of sunscreen just for your face,” advises Dr. Vandenberg (13:23). She highlights that most people underestimate the quantity needed for effective protection.
   • Reapplication:
     Sunscreen should be reapplied every 90 minutes, especially when outdoors for extended periods. An indicator of insufficient application is depleting your sunscreen bottle too quickly—“If a bottle expires under your sink at home, you weren't using enough,” warns Dr. Vandenberg (14:08).

3. Sunscreen Checklist:
   Dr. Gupta summarizes key takeaways for effective sunscreen use:

   • Choose Broad Spectrum: Protect against both UVA and UVB rays.
   • SPF Rating:
     “SPF 30 plus is the minimum recommendation,” notes Dr. Neal (12:48). Higher SPF levels offer added protection, but proper application is crucial.
   • Adequate Application: Use sufficient amounts—three fingers’ worth for the face.
   • Regular Reapplication: Every 90 minutes when outdoors.
   • Proper Storage: Keep sunscreen in cool places to prevent degradation of active ingredients.
   • Complementary Protection: Utilize hats, shade, and sun-protective clothing for enhanced safety.

---

Conclusion

In this episode of Chasing Life, Dr. Sanjay Gupta provides a comprehensive guide to balancing sun exposure for optimal health. By understanding the benefits of morning sunlight for both mood and eye health, recognizing the dangers of midday UV rays, and mastering the art of effective sunscreen use, listeners are equipped to enjoy a safe and healthy summer. The episode underscores the importance of informed sun safety practices in promoting overall well-being.

---

Timestamps

• [00:43] Deirdre’s initial question about sunlight exposure.
• [03:21] Dr. Raj Muturi on morning sunlight benefits.
• [04:42] Dopamine release and myopia prevention.
• [05:22] Risks of midday sun exposure.
• [07:23] Fireworks safety reminder.
• [10:30] Kira’s question on sunscreen.
• [11:25] Dr. Rachel Neal on types of sunscreens.
• [12:48] Dr. Neal’s SPF recommendation.
• [13:23] Dr. Vandenberg on sunscreen application.
• [14:08] Indicators of insufficient sunscreen use.

Note: Timestamps correspond to the provided transcript segments.

Transcript

[Sanjay Gupta]

Welcome to Paging Dr. Gupta. Thanks so much for joining us. It is the week of July 4th. Summer is in full swing. The season is heating up, and you've had a lot of related questions. You know, I love these episodes because they're all about you, and I get a chance to hear about the concerns that you have that you're living through right now. So let's get straight into it. Kira's back with us. Who do we have first?

[Kira Daring]

All right. Hey, Sanjay. So our first question today is coming from a listener in Philadelphia. And as you just said, summer is officially here. I feel like this question has gotta be on a lot of people's minds. Take a listen.

[Deirdre]

Dr. Gupta, my name is Deirdre. A friend of mine said that a doctor told her that our eyes should get certain amount of unfiltered sunlight per day. And I was really surprised because I've had an eye doctor tell me to wear sunglasses all the time. So, yeah, what's the truth to, you know, sort of like how you get 10 minutes of sunlight on your skin without sunscreen?

[Sanjay Gupta]

I just.

[Deirdre]

I just can't believe it. So, Dr. Gupta, what do you say about the sunlight in the eyes? Thanks so much.

[Sanjay Gupta]

Okay, Kira, thank you. And Deirdre, that is a great question, Honestly, something that I've thought about myself. A lot of people have been wondering about, and I'm going to give you as detailed an answer as I can in just a minute.

[Advertisement Speaker]

When something's made for you, it simply fits. You feel special. That's the sensation of a sleep number smart bed. You'll sleep comfortably, hot or cold, soft or firm. Because it's personalized, scientifically made for you. Sleep number Smart beds learn how you sleep and provide personalized insights to help you sleep better. Why choose a Sleep number smart bed? So you can choose your ideal comfort on either side. The only bed that lets you make each side firmer or softer. Whenever you like Your sleep number setting. And now it's the Sleep Number 4th of July Sale. Save over $600 on the Sleep Number P5 King Smart Bed, the lowest price of the season. Limited time, exclusively at a sleep number store near you. Save store or sleepnumber.com for details.

[Carl Zimmer]

Chasing life is supported by the world as you'll know it, a podcast about the forces shaping the future. In this season, host and science journalist Carl Zimmer speaks to some of the most respected scientists in the field of aging research about the massive changes in human longevity and what comes next. Is our lifespan set? Or will a breakthrough add decades to our lives. Can older brains be rewired to function like younger ones? Which so called biohacks actually work? The world as you'll know it is available now.

[Sanjay Gupta]

Let me start by this There is some confusion I think overall just when it comes to sunlight and your eyes. So one of the things I get to do on this podcast is call people who are the world experts in these various areas, world experts who can come on the podcast to help answer your questions. So we called up Dr. Raj Muturi. He's an ophthalmologist, he's got 25 years of experience. He's also a spokesperson for the American Academy of Ophthalmology. We asked him this question, here's what he said.

[Dr. Raj Muturi]

How much unfiltered sunlight should you receive? Take home message. Aim for 10 to 15 minutes of direct unfiltered morning light. No windows, no sunglasses. As soon as practical after waking up. In fact, the best and safest time to do it is in the first 45 minutes after the sun rises. We need to have a circadian reset at the retinal level.

[Sanjay Gupta]

So why early morning? Well, turns out there's a pretty fascinating reason for this.

[Dr. Raj Muturi]

Early in the morning, the sun is coming at a pretty acute angle on the atmosphere. A lot of the bad stuff, the UVB light, the really short wavelength light that's bad for us, jumps off the atmosphere. So we don't get that. Our skin doesn't get that. And therefore it doesn't get red even if you're outside 10, 15 minutes. A clear sign that it's still safe. And your sunburn risk is almost zero at that early point in the morning. And it allows your vitamin D production to happen.

[Sanjay Gupta]

So again, just to reset morning light in particular, Deirdre, that's what you got to pay attention to. Helps reset your circadian rhythm, boost mood, improve sleep, give you a skin safe dose of sunshine so that your body can make vitamin D. And get this, Dr. Muturi says it's even more than that. Having that sort of sunlight can actually play a role in preventing nearsightedness, especially in kids.

[Dr. Raj Muturi]

When you have bright outdoor light like 10,000 plus lux, which happens first thing in the morning, it triggers dopamine release in the inner retina. And this dopamine is the principal stop signal that keeps the eyeball from lengthening. And our eyeball is at most risk for lengthening in the first 20 years of life. And this is data that's been clearly shown published 20 to 50% lower incidence of myopia and slower Progression when daily outdoor time is front loaded in the beginning of the day.

[Sanjay Gupta]

But now this is the important part. He says that as sun climbs higher in the sky, it is time to switch gears.

[Dr. Raj Muturi]

It's really critical, especially if you're supremely light skinned, if you're, you know, light colored hazel eyes or blue eyes that you have some sun protection on for midday sun, definitely after kind of 10am to 4pm that's when 50% of our daily UV dose happens. So when the sun is so much stronger, you definitely want to have protection both on your skin and on your eyes.

[Sanjay Gupta]

That midday sun can do real damage over time. In the short term, it can cause sunburned eyes, something called photokeratitis. It can show up as redness, watery eyes, even blurry vision. That usually clears up within a day or two. But there are long term risks that are more serious. One of the biggest, something known as macular degeneration. That's when the center part of your retina, called the macula, starts to break down. And that can lead to blurry vision or even permanent blind spots. And while it's more common as we age, too much sun exposure over the years can definitely raise your risk.

[Dr. Raj Muturi]

About a third of Caucasian populations have a higher risk for macular degeneration, and many of them develop it. 30% of the population who's over 80 has significant macular degeneration and smaller percentages over 60 and 70 years of age. So all of that happens in many ways due to oxidative damage from food, from high blood pressure, from being overweight and also being exposed to too much direct sunlight.

[Sanjay Gupta]

Dr. Maturi also said that there are some studies that show UV ray exposure can increase the risk of cataracts. So to sort of summarize here, Deirdre, aim for 10 to 15 minutes of early unfiltered sunlight every morning timeframe is really important here. But after that, protect your eyes. Use polarized sunglasses, especially if you're around water or sand. And one last thing. Since fireworks season is here, Dr. Muturi had a quick safety reminder.

[Dr. Raj Muturi]

July 4th is right upon us. And a small tip. Wear safety glasses when you're with fireworks. As a retina specialist for the last 25 years, I have operated on July 5th, 6th and 7th, fixing eyes that are often irreparably broken. Launch injury is so big, so common and fireworks are everywhere. Everybody wants to use them, especially kids. 90% of it is towards men. So the men out there, be super careful. Please don't be that statistic. Save those pretty eyes. Because eyes are delicate, so have them protected.

[Sanjay Gupta]

Coming up. You know, sunscreen's important for sure, but how much should you be using? We get so many questions about that. And does that old bottle in your cabinet still work? We'll have that right after the break.

[Advertisement Speaker]

This CNN podcast is supported by Sleep Number when something's made for you, it simply fits. You feel special. That's the sensation of a Sleep Number Smart bed. You'll sleep comfortably, hot or cold, soft or firm, because it's personalized, scientifically made for you. The tech in a Sleep Number Smart bed automatically responds to your movements throughout the night, keeping you comfortable and most importantly, sleeping soundly. Sleep the Klymit Series Smart beds cool up to 20 times faster than leading competitors. Getting great sleep is the journey of a lifetime. And your Sleep Number Smart bed tracks the evolution and improvement of your sleep for you and your partner. It's designed to make each night's rest even better. Why choose a Sleep Number Smart bed? So you can choose your ideal comfort on either side. The only bed that lets you make each side firmer or softer whenever you like Your Sleep Number setting. And now it's the Sleep Number 4th of July sale. Save over $600 on the SleepNumber P5 King Smart Bed, the lowest price of the season. Limited time exclusively at a Sleep Number store near you. See store or sleepnumber.com for details.

This podcast is supported by Dell. Introducing the new Dell AI PC. Powered by the Intel Core Ultra processor. It's not just an AI computer, it's a computer built for AI. That means it's built to help do your busy work for you so you can fast forward through editing images, designing presentations, generating code, debugging code, running lots of apps without lag, creating live translations and captions, summarizing meeting notes, extending battery life, enhancing security, finding that file you were looking for, managing your schedule, meeting your deadlines, responding to Jim's long emails, leaving all the time in the world for more you time and for the things you actually want to do. No offense, Jim. Get a new Dell AI PC starting at $749.99 at Dell.comai-PC how those ahead Stay ahead.

[Sanjay Gupta]

All right, Kira, time for another question. Take it away.

[Kira Daring]

Well, Sanjay, Deirdre's question kind of got me thinking. So now that we know a little bit of morning sun can actually be good for us, what about all that time after? I feel like sunscreen is a bit of a mystery at times. So what kind should we be using? You know what SPF level or how much is actually enough to protect us?

[Sanjay Gupta]

Okay, Kira, this is a great question because all the options really can sometimes be confusing. On a past episode of Chasing Life, we went straight to the experts to sort these things out and importantly, to find out what these experts actually do themselves. I find that you can get great insights by asking people how they incorporate their own knowledge into their daily lives. So first up, epidemiologist Dr. Rachel Neal, to help explain the two types of minerals, also called physical sunscreen and chemical.

[Dr. Rachel Neal]

The physical blockers. So the titanium and zinc sunscreens, they sit on top of the skin basically and form a barrier, whereas the chemical sunscreens, they sort of bind to the top surface of the skin and turn the UV radiation into heat and then disperse it from the body as heat. I think it's very tricky because the properties of the chemical sunscreens make them much more pleasant to use. The physical blockers tend to be a bit thicker and they can form a bit of a white veil on the skin. So from a just usability perspective, I use a chemical sunscreen every day.

[Sanjay Gupta]

So think of physical sunscreen as forming a literal physical shield on your skin, while chemical sunscreens absorb and then deflect UV rays. Now, whichever type you pick, it comes down to what works for your skin and your routine. So what should that routine be?

[Dr. Rachel Neal]

We actually formally recommend that people should apply sunscreen routinely on all days when the UV index is forecast to get to three or more. So we're advising people to make it as routine as brushing their teeth. But on those days when the UV index is not going to get to above 3, we're seeing suggesting that sunscreen is not needed.

[Sanjay Gupta]

Okay, that helps. What about other qualities? First, choose a broad spectrum sunscreen to make sure you have protection from UVA and UVB rays. Hopefully you know that. As for SPF, well, Dr. Neal says 30 plus is the minimum recommendation. Some people might prefer 50 plus for added coverage, but this is the key. It's not just about spf.

[Advertisement Speaker]

It's about.

[Sanjay Gupta]

It's about how much you're actually using and how often you're applying it. And that's where Dr. Laura Vandenberg, a public health scientist at the University of Massachusetts Amherst, has some thoughts.

[Dr. Laura Vandenberg]

Based on what I know and in my own practice, lean towards a physical sunscreen and then use correctly. Right. More than you think you need. And reapplying every 90 minutes, most of us put on the amount of sunscreen that we feel is sort of enough so I can't see it. Right. You know, you rub it into your skin. Skin, but that's not actually the way that they're intended to be used to protect us. So a colleague of mine would say three full fingers of sunscreen just for your face. So we're not putting on enough. And really we should be putting on that amount on your face every 90 minutes if you're outside.

[Sanjay Gupta]

She also says how slowly you go through your sunscreen might be an indicator that you're not using enough.

[Dr. Laura Vandenberg]

In a couple days, you should use up the bottle. So if you have sunscreen that's expiring under your sink at home, number one, throw it out. But number two, you weren't using enough when you were using that product.

[Sanjay Gupta]

One last tip. Don't store sunscreen in hot places like your car. Why? Heat can actually break down the active ingredients, making that sunscreen less effective. So let me try and summarize this. Think of this as your sunscreen checklist. Number one, choose a broad spectrum sunscreen that works for you. Can be physical or chemical. Number two, use enough. Remember, three fingers worth just for your face. Number three, reapply every 90 minutes when you're outdoors. Number four, make it a daily habit. Whenever the UV index is three or higher, you can check that. Number five, store your sunscreen somewhere cool. And finally, don't forget the other basics. Hats, shade, sun protective clothing. They all go a long way. That's it for paging Dr. Gupta today. Wishing you all a safe and sunny summer. Thanks to everyone who sent in questions. I really appreciate that we are building this show together. You're a big part of it. If there's something health related you've been curious about, don't be shy. Share it. Record a voice memo, email it to asksanjaynn.com or give us a call. 470-396-0832. Leave a message. Thanks for listening and I'll be back next Tuesday. Chasing Life is a production of CNN Audio. Our podcast is produced by Aaron Mathewson, Jennifer Lai, Grace Walker, Lori Gallaretta, Jesse Remedios, Sofia Sanchez, Kira Daring and Madeline Thompson. Andrea Kane is our medical writer. Our senior producer is Dan Bloom. Amanda Seeley is our showrunner. Dan Dijiula is our technical director. And the executive producer of CNN Audio is Steve Lichtai with support from Jamis Andrest, John Dianora, Hayley Thomas, Alex Manasseri, Robert Mathers, Lainey Steinhardt, Nicole Pesaru and Lisa Namoro. Special thanks to Ben Tinker and Nadia Kanang of CNN Health and Wendy Brundage.

[Advertisement Speaker]

This CNN podcast is supported by Sleep Number when something's made for you, it simply fits you feel special. That's the sensation of a Sleep Number Smart bed. You'll sleep comfortably, hot or cold, soft or firm because it's personalized, scientifically made for you. The tech in a Sleep Number Smart bed automatically responds to your movements throughout the night, keeping you comfortable and most importantly, sleeping soundly. Sleep Too hot the Klymit series Smart beds cool up to 20 times faster than leading competitors. Getting great sleep is the journey of a lifetime, and your Sleep Number Smart Bed tracks the evolution and improvement of your sleep for you and your partner. It's designed to make each night's rest even better. Why choose a Sleep Number Smart Bed? So you can choose your ideal comfort on either side. The only bed that lets you make each side firmer or softer whenever you like your Sleep Number setting and now it's the Sleep Number 4th of July Sale. Save over $600 on the Sleep Number P5 King Smart Bed, the lowest price of the season. Limited time, exclusively at a Sleep Number store near you. See store or sleepnumber.com for details. The HBO Original series the Gilded Age is back, and so is the official companion podcast.

[Deirdre]

Are you curious about how they brought Gilded Age New York to life?

[Dr. Raj Muturi]

I don't understand. Which bit is not clear?

[Sanjay Gupta]

None of it is clear.

[Advertisement Speaker]

Want to know where the writers branched off from history?

[Sanjay Gupta]

Well, when you set your mind on a thing, no one can stop you.

[Dr. Laura Vandenberg]

I take that as a compliment.

[Sanjay Gupta]

Watch or listen to the official Gilded.

[Deirdre]

Age Podcast wherever you find podcasts.