How Long Should I Use Blue Light? The Surprising Truth

Honestly, blue light is everywhere nowadays, right? You’re probably staring at your phone or computer screen as we speak, and that blue light is hitting your eyes. But how long should you really use it? Is there a limit? I’ve had this question too, especially after hearing so much about the potential harms of blue light exposure. Let’s break it down together and see what science says, along with some practical tips from my own experience.

What Exactly is Blue Light?

Before we dive into how long you should use blue light, it’s essential to understand what blue light is and where it’s coming from. Blue light is part of the visible light spectrum, and it has a shorter wavelength than most other colors. It’s the kind of light emitted from our digital screens, like your phone, tablet, and computer, as well as artificial lighting.

Blue Light and Its Effects on Your Body

Honestly, the big deal about blue light is that it has more energy than other types of visible light. This means it can potentially penetrate deeper into your eyes. Now, while blue light can help regulate your circadian rhythm (you know, your body’s sleep-wake cycle), it’s also linked to eye strain and, depending on exposure, could even disrupt your sleep.

I remember a time when I was staying up late reading on my phone, and the next morning, I felt like I’d barely slept. Could it have been the blue light? Yeah, probably.

How Long Should You Use Blue Light in a Day?

Okay, now let’s get to the heart of the matter—how long is too long? Well, it depends on the situation and how much you’re exposed to it.

Daily Exposure to Blue Light

For most of us, blue light exposure is almost unavoidable. We’re surrounded by screens all day long. But experts generally recommend limiting prolonged exposure to blue light, especially in the evening. If you can’t avoid using digital devices all day, the key is moderation.

How Much Time Should You Spend on Screens?

According to some studies, it’s safe to spend about 2-3 hours in front of screens, but more than that, and you might start feeling the effects like eye fatigue or disrupted sleep. That said, everyone’s different. I’ve personally noticed that after 4-5 hours of screen time, my eyes start to feel dry, and I’m more likely to get a headache. You know your body better than anyone else!

Blue Light Exposure at Night

Here’s the real kicker—using blue light late at night. This is where things can get tricky. Blue light, especially from phones or computers, can trick your brain into thinking it’s still daylight, which can mess with your sleep cycle. I learned this the hard way when I started using my phone right before bed—sleeping became way harder than usual.

The 20-20-20 Rule

A cool tip I came across (and totally recommend) is the 20-20-20 rule: for every 20 minutes you spend looking at a screen, look at something 20 feet away for 20 seconds. It’s supposed to reduce eye strain, and honestly, it works! I’ve been trying it lately, and my eyes feel way less tired.

Can Blue Light Be Good For You?

Wait, blue light is bad, right? Actually, blue light isn’t all bad. It helps boost your alertness and cognitive function during the day. Some researchers even say it can improve your mood and reaction time. So, you definitely don’t want to cut yourself off completely. The trick is balancing it, especially when it comes to the timing.

Blue Light in Moderation

Blue light can actually help keep you awake and alert during the day, which is why it's used in some therapy treatments for Seasonal Affective Disorder (SAD). I’ve had friends who’ve used light therapy in the winter to combat the lack of sunlight, and it really seems to help them feel more energized.

How Can You Protect Yourself From Too Much Blue Light?

Alright, so if you want to keep using blue light but minimize the bad effects, what can you do? I’ve picked up a few tricks that work well.

Use Blue Light Filter Glasses

One option that helped me is wearing blue light blocking glasses. These glasses have a special coating that blocks out a significant portion of the blue light. I was skeptical at first, but after using them for a week, I felt less eye strain, and I noticed my sleep wasn’t as disrupted.

Adjust Your Screen Settings

Most devices have settings where you can adjust the screen to reduce blue light exposure, especially in the evening. For instance, there’s the “night shift” mode on iPhones and a similar feature on many Android devices. Honestly, I feel like it’s a small change, but it makes a huge difference.

Limit Screen Time Before Bed

This is something I still struggle with sometimes, but try to stop using screens at least 30 minutes before bed. It sounds easy, but it’s tough when you’re binge-watching a show or scrolling through your phone. That said, I can say from experience that cutting out screen time before bed does wonders for your sleep quality.

Conclusion: How Long Should You Use Blue Light?

So, how long should you use blue light? Honestly, a couple of hours a day is totally fine, but be mindful of your exposure, especially before bed. The key is balance. Take regular breaks, use blue light filters, and try to minimize your screen time late at night. Your eyes—and your sleep—will thank you!

And hey, if you’re still unsure, start paying attention to how your body feels after long screen sessions. I did, and now I’m way more conscious of when I need a break!

Is 165 cm normal for a 15 year old?

The predicted height for a female, based on your parents heights, is 155 to 165cm. Most 15 year old girls are nearly done growing. I was too. It's a very normal height for a girl.

Is 160 cm too tall for a 12 year old?

How Tall Should a 12 Year Old Be? We can only speak to national average heights here in North America, whereby, a 12 year old girl would be between 137 cm to 162 cm tall (4-1/2 to 5-1/3 feet). A 12 year old boy should be between 137 cm to 160 cm tall (4-1/2 to 5-1/4 feet).

How tall is a average 15 year old?

Average Height to Weight for Teenage Boys - 13 to 20 Years

How to get taller at 18?

Staying physically active is even more essential from childhood to grow and improve overall health. But taking it up even in adulthood can help you add a few inches to your height. Strength-building exercises, yoga, jumping rope, and biking all can help to increase your flexibility and grow a few inches taller.

Is 5.7 a good height for a 15 year old boy?

Generally speaking, the average height for 15 year olds girls is 62.9 inches (or 159.7 cm). On the other hand, teen boys at the age of 15 have a much higher average height, which is 67.0 inches (or 170.1 cm).

Can you grow between 16 and 18?

Most girls stop growing taller by age 14 or 15. However, after their early teenage growth spurt, boys continue gaining height at a gradual pace until around 18. Note that some kids will stop growing earlier and others may keep growing a year or two more.

Can you grow 1 cm after 17?

Even with a healthy diet, most people's height won't increase after age 18 to 20. The graph below shows the rate of growth from birth to age 20. As you can see, the growth lines fall to zero between ages 18 and 20 ( 7 , 8 ). The reason why your height stops increasing is your bones, specifically your growth plates.