Bearded Dragon UV & Solar Radiation: Comprehensive Guide

Bearded dragon UV lighting helps them to regulate everything from metabolism to natural behaviors. Here we look at what UV light a bearded dragon needs and what it does for them.

Did you know that if a bearded dragon isn’t active or has no interest in eating are symptoms of incorrect lighting?

Do you know that thinner-scaled morphs, like Silkbacks, reduce their exposure to UV?

This article is part 1 of the 5 part series:

1. Bearded Dragon UV & Solar Radiation: Comprehensive Guide – this article.
2. Bearded Dragon Heat Lamp and Equipment List: What you Need – making your choices of lighting and heating easier.
3. How to Choose the Best Thermostat for Bearded Dragons – types of thermostats and some brands.
4. Bearded Dragons Lighting & Heating: The Ultimate Guide – bringing it all together with temperatures and lighting cycles.
5. The Worst Lights for Bearded Dragons: A Complete Guide – A look at all the lighting and heating our bearded dragons don’t need which cause problems.

Bearded Dragon UV: Why the Bands Matter

When it comes to our bearded dragon’s health, the type of light they’re exposed to can make all the difference.

Solar radiation encompasses five main bands being UVC, UVB, UVA, visible light, and infrared. UVC is dangerous to us all but doesn’t get past the atmosphere. The remaining bands make up everything our bearded dragons need for their well-being.

It is the UVB, UVA, visible light, and infrared that we bring together in our enclosures, trying to mimic the sun’s natural spectrum of wavelengths.

It is not easy for artificial lighting that we use in our indoor enclosures to replicate the benefits of natural sunlight. Which is why we need to understand the roles of each part of the spectrum and how to provide balanced lighting for our bearded dragon’s. If any of the bands are missing, things are off for our beardies.

Bearded dragons evolved under the balanced light spectrum of the sun. Each radiation band (except UVC) are needed to function.

🚫Ultraviolet C (UVC): The Invisible Danger

UVC from the sun is harmful to all of us and luckily filtered by Earth’s atmosphere, but that is not always the case with artificial lighting. Some UV bulbs for bearded dragons have been found to emit UVC, we will look at that later.

• Wavelength: 180–280 nm
• What UVC for bearded dragons does: UVC is dangerous and harmful to all life forms, including our bearded dragons. Thankfully, Earth’s atmosphere filters out most UVC radiation before it reaches the ground (Wilkinson, 2015).
  It can cause severe damage to skin and eyes, leading to conditions such as burns, photo-kerato-conjunctivitis, and long-term cellular damage (Wunderlich et al., 2023).
• Additional Insights: Some low-quality artificial UVB lamps, especially cheaper UVB-LEDs, may emit harmful UVC radiation.
  Always choose tested and reptile-safe lighting options to protect our bearded dragons from the invisible UVC hazard (Wunderlich et al., 2023).
• Human Comparison: UVC is like standing too close to a welding torch without protection—it’s powerful enough to cause burns and damage to skin and eyes.
• Pro Tip: Think of UVC as the invisible “danger zone” of light. Always choose tested, high-quality, reptile-safe UV lighting (Wunderlich et al., 2023).

⭐Ultraviolet B (UVB): The Calcium Converter

UVB is the one you hear about most of the time. Our bearded dragons UV is incomplete without UVB which enables the synthesis of vitamin D³ so they can absorb calcium.

• Wavelength: 280–315 nm
• What UVB for bearded dragons does: UVB for bearded dragons is essential to produce vitamin D³ in their skin. Vitamin D³ allows their bodies to absorb calcium.
  Without UVB, they’re at risk of developing metabolic bone disease, a painful and preventable condition.
• Additional Insights: Not all UVB lights for bearded dragons are created equal. Natural sunlight contains longer wavelengths in the UVA2 range (315-335 nm) that regulate vitamin D³ production, preventing overproduction. Many artificial UVB lights, particularly UVB-LEDs, lack these wavelengths, increasing the risk of hypervitaminosis D if exposure is not carefully monitored (Wunderlich et al., 2023).
  UVB cannot pass through glass, acrylic or other barriers.
  Bearded dragons instinctively adjust their UV exposure based on their environment and skin type. Thinner-scaled morphs, like Silkbacks, reduce their exposure compared to wild types, highlighting the importance of providing a UV gradient (Sakich & Tattersall, 2022).
• Pro Tip: Even with the right diet, your bearded dragon can’t process calcium properly without UVB light.

⭐Ultraviolet A (UVA): The Mood and Behavior Booster

UVA (“mood lighting”) helps regulate behaviors like feeding, basking, and mating, keeping our bearded dragon active and happy. Without it, their activity levels and natural instincts may diminish.

• Wavelength: 315–400 nm
• What UVA for bearded dragons does: Think of UVA as the light that makes our bearded dragons feel good. UVA helps to stimulate our bearded dragon’s natural behaviors and enables them to self-regulate exposure to UV radiation.
  The UVA band influences how they:
  • Perceive their environment,
  • Recognize food,
  • Interact with their surroundings,
  • Regulate basking – determine how much UV and heat they are receiving, allowing them to move when they’ve had enough (Sakich and Tattersall, 2022).
  • Gives beardies motivation to explore or eat (Wunderlich et al., 2023).
  • Mating and Social Interactions: UVA stimulates activity and courtship behavior.
• Without UVA, these natural instincts may diminish, leading to reduced appetite, inactivity, or stress. It also disrupts their ability to self-regulate UV exposure, increasing the risk of overexposure or deficiency (Sakich & Tattersall, 2022; Baines, 2017).
• Additional Insights: UVA is a form of ultraviolet light. UVA is invisible to us but bearded dragons and many other animals like birds, some insects and reptiles can.
  UVA works alongside UVB to create a balanced lighting environment.
  While UVA does pass through glass more effectively than UVB, there is still some loss, particularly with thicker glass.
• Human Comparison: UVA is like the warm glow of a sunny day that lifts your spirits and gets you moving. Without it, you’d feel sluggish and unmotivated.
• Pro Tip: Think of UVA as the “mood lighting” your bearded dragon needs to feel curious, happy, and active.

⭐Visible Light: The Activity Starter

Visible light drives activity and interaction with the environment, so our bearded dragons can be engaged and alert.

• Wavelength: 400–700 nm
• What visible light for bearded dragons does: Visible light for bearded dragons keeps them active and engaged.
• Additional Insight: Visible light doesn’t just brighten the enclosure; it also plays a role in our bearded dragon’s perception of UV radiation. Poorly balanced artificial lighting can disrupt how our bearded dragons perceive their environment, potentially reducing their ability to self-regulate UV and heat exposure (Wunderlich et al., 2023).
  A bright, full-spectrum light simulates daylight and encourages natural behavior like hunting, exploring, and basking (Baines, 2017).
• Human Comparison: A long and dark winter can impact humans significantly and cause depression. Similarly, without bright visible light, our bearded dragons can feel disengaged, become less active, lose interest in their surroundings, and stop engaging in natural behaviors.
• Pro Tip: A brightly lit enclosure mimics the sun’s rays and keeps your bearded dragon engaged. Keep your bearded dragons enclosure well lit during the day.

⭐Infrared: The Heat Provider

Infrared radiation provides essential warmth for thermoregulation, digestion, and metabolic processes.

• Wavelength: 700 nm and above
• What infrared for bearded dragons does: Infrared for bearded dragons provides the warmth they need for thermoregulation. Proper heating is vital for digestion, activity levels, and overall metabolic health (Divers and Mader, 2006).
• Additional Insight: Bearded dragons instinctively bask under infrared light to warm up, especially in cooler areas.
  Temperature and UV exposure are interlinked: bearded dragons in lower temperatures chose higher UV exposure to balance their heat and vitamin D needs (Sakich and Tattersall, 2022).
  Avoid using lamps that emit both infrared and unsafe UV wavelengths, like certain UVB-LEDs. Ensure your lighting and heating systems work together to create a safe and natural environment (Wunderlich et al., 2023).
• Human Comparison: We don’t rely on external heat to survive since we’re endotherms (we generate our own body heat). But think of infrared radiation like sitting outside in the sun or next to a fire on a cold day. For bearded dragons, as ectotherms, this warmth isn’t just nice—it supports their bodily functions.
• Pro Tip: Bearded dragons are ectothermic, meaning they rely on external heat sources to regulate their body temperature.

Bearded Dragon UV in Practice: A Guide to Getting It Right

Why we Need to Get Bearded Dragon UV Lighting Right

Providing our bearded dragons with proper UV lighting is about recreating the balanced light spectrum they naturally experience in the wild. That is a tough gig!

Unbalanced artificial lighting can disrupt how reptiles perceive their environment. For instance, one study found that a tested lamp emitted a disproportionately high UVA ratio (41%) compared to visible light (52%), which could make the light appear “UVA-colored” to reptiles. This imbalance may distort their behavior and impact their ability to regulate UV exposure effectively (Wunderlich et al., 2023). How do we avoid crappy UV for our bearded dragons? We measure and monitor and that is what this section is about.

We’ve already covered the details of UVA, UVB, visible light, and infrared, so you know what each band does. Fortunately our bearded dragons instinctively move between UV-rich basking spots and shaded retreats to self-regulate their UV exposure, just as they do in the wild (Sakich & Tattersall, 2022). This means we just have to set up our enclosures correctly and then let our bearded dragon do its thing.

But, artificial lighting often struggles to perfectly replicate sunlight, and without proper care, it can lead to unbalanced UV exposure that affects our dragon’s health and behavior. Plus we need to use high-quality equipment to help bridge the gap between real sunlight and artificial lighting (Wunderlich et al., 2023).

🦎UV to Infrared: Real vs. Artificial

When it comes to providing UVB lighting for your bearded dragon, the source matters. While artificial lighting is essential for indoor setups, natural sunlight remains the benchmark for UVB exposure. Here’s how each source compares:

Outdoors: Natural Sunlight for Bearded Dragons

Natural sunlight is gold to bearded dragons. Sunlight offers a perfectly balanced spectrum of light, designed by nature to meet our bearded dragons needs.

What Sunlight Offers	Why It Matters
Balanced UV Spectrum	Sunlight delivers a natural mix of UVB, UVA, visible light, and infrared, ensuring your dragon gets the full benefits without risks from imbalanced wavelengths (Mans & Braun, 2014).
Vitamin D3 Synthesis	Direct sunlight provides optimal UVB radiation, including the 315–335 nm range critical for regulating vitamin D3 production and preventing overproduction (Wunderlich et al., 2023).
Behavioral Benefits	Basking in natural sunlight allows dragons to self-regulate their UV exposure and engage in natural behaviors like thermoregulation and activity cycles (Sakich & Tattersall, 2022).

What to do	How to do it
Sunshine Sessions	Allow your bearded dragon to bask outdoors, depending on the season and temperature. Always provide shaded areas for them to retreat and self-regulate (Sakich & Tattersall, 2022).
Avoid Barriers	Never place your dragon behind glass or acrylic outdoors. These materials block most UVB rays, defeating the purpose of sunlight exposure. If using an enclosure, opt for mesh or open designs.
Don’t use glass tanks outside	Additionally, glass acts as a magnifier in direct sunlight, creating a greenhouse effect that can dangerously overheat the enclosure, potentially causing heatstroke. If using an outdoor enclosure, choose mesh or open designs that allow UV rays to pass through freely.
Monitor Temperatures	Outdoor temperatures can quickly rise. Ensure the environment is safe and suitable for your dragon’s needs.

It needs to be remembered that most forms of artificial UV-B radiation provided in
captivity are only an inadequate supplement for natural sunlight that most reptiles
are exposed to in their natural habitat.

Mans & Braun (2014)

Indoors: UV to Infrared for Bearded Dragons

Of course natural sunlight provides the best UV spectrum for bearded dragons, but many of us keep them indoors. Some of the wavelengths found in sunlight are missing in artificial light, like the UVA2 band (315–335 nm) (Wunderlich et al., 2023).

To come close to matching sunlight we need to invest in the right equipment and lights.

There is a complete guide on setting up heating and lighting for your bearded dragon (I gave the link previously). But just to touch on the subject for you on the best UV lighting for bearded dragons T5-HO fluorescent tubes or the Mercury vapor lamps along with the right heating and basking lights of course.

While artificial UVB bulbs are essential for indoor enclosures, they come with notable limitations:

• Incomplete Spectrum: Many artificial UVB bulbs fail to replicate the full range of wavelengths found in natural sunlight, including the crucial UVA2 band (315–335 nm). This gap can disrupt the regulation of vitamin D³ production, increasing the risk of metabolic imbalances like hypervitaminosis D (Wunderlich et al., 2023).
• Risk of Harmful Radiation: Poor quality UVB-LED lamps may emit dangerous wavelengths, including UVC radiation. UVC wavelengths, such as those peaking at 277 nm and 280 nm, are not present in natural sunlight and can cause severe conditions like photo-kerato-conjunctivitis and skin damage (Wunderlich et al., 2023). Always choose tested, reptile-safe lighting options to avoid these hazards.
• Behavioral Gaps: Even high-quality artificial lighting often lacks the intensity and balance of natural sunlight, including the full UVA spectrum needed for proper behavioral stimulation. This can lead to reduced activity levels and disrupted natural behaviors, such as basking and feeding.
• Short Lifespan and Degradation: Artificial UVB sources degrade over time, with many losing effectiveness within 6–12 months. This reduction in UVB output can compromise your bearded dragon’s health if bulbs are not replaced regularly. Using a UV index meter to monitor levels is critical to maintaining proper UVB exposure (Wunderlich et al., 2023).

Bearded Dragons & the UV Index: What we Need to Measure & How

The UV Index (UVI) is a measure of how strong the UVB radiation is in a specific area. For our bearded dragons, having the right UVI is like setting the perfect thermostat—but for sunlight. Too little UVB can weaken their bones (metabolic bone disease), while too much can stress or even cause burns.

Zone	Ideal UVI	Why It Matters
Basking Zone	3–7	Mirrors wild conditions, allowing for vitamin D3 synthesis.
Shaded Areas	Minimal to no UV exposure	Provides a retreat to avoid overexposure and regulate body temperature.

To put this into perspective, a UVI of 3–7 mimics the midday sunlight in their native Australian habitat. By giving our bearded dragons UV of 3 to 7 they receive just enough UVB for vitamin D³ production while allowing them to retreat to shaded areas to avoid overexposure.

Here is how to check if you have a UVI of 3–7.

What to do	Description
Use a UV Index Meter	These tools measure UVB radiation for our bearded dragon’s enclosure and provide an exact UVI reading. Handheld meters are widely available online and at pet stores.
Where to Test	Place the meter in your bearded dragon’s basking area at the same height they would be while basking.
What to Look For	Ensure the basking zone has a UVI of 3–7, mimicking the midday sun in their natural habitat.
Check Your Bulb Specifications	A T5-HO fluorescent tube can provide UVI 3–7 at 12–18 inches with a reflector. Mercury vapor bulbs usually produce higher UVB levels but need specific placement.

If you can’t measure it, you can’t improve it.

Peter Drucker

☀️How do I know if my Bearded Dragon is Getting Enough UV?

Bearded dragons are not passive sunbathers; they actively manage their UV exposure. You will see your bearded dragon managing its UV when it self regulates showings signs of moving around into different areas of its enclosure to get closer to or further away from the basking area.

Behavior	How bearded dragons show they are self regulating UV
Self-Regulation	In the wild, bearded dragons bask in sunlight to absorb UVB for vitamin D3 production, then retreat to shade when they’ve had enough.
Behavioral Cues	Basking: Indicates they’re soaking up UVB for calcium metabolism and overall health. Retreating to Shade: Signals they’ve had enough UV or need a cooler spot.

Invest in high-quality, reptile-safe lighting and set it up right. Regularly monitor UV levels using a UV index meter, and replace bulbs as recommended to maintain consistent, safe UV exposure. This simple step can go a long way in protecting your bearded dragon’s health.

If a bearded dragon doesn’t get enough UV it will show through health issues (like MBD) and behavioral issues like not being interested in what is going on around it.

Underexposure Risks	Description
Metabolic Bone Disease (MBD)	Without sufficient UVB, your bearded dragon cannot produce vitamin D3, which is essential for calcium absorption. This leads to brittle bones, deformities, and impaired muscle function, a condition known as metabolic bone disease (Mans & Braun, 2014).
Behavioral Issues	Lack of UVA can result in lethargy, reduced appetite, and lack of interest in their surroundings. UVA plays a key role in regulating behavior, such as feeding, basking, and mating (Baines, 2017; Sakich & Tattersall, 2022).

🕶️Can a Bearded Dragon get too much UV Light?

Yes, bearded dragons can get too much UV light, which can lead to several health issues. When a bearded dragon is overexposed to UV radiation serious problems will occur including:

• Physical Damage: Excessive UV exposure can result in burns, eye damage, and skin problems. This is particularly concerning with artificial UVB sources that may emit harmful UVC wavelengths not present in natural sunlight like some of the cheap bulbs.
• Metabolic Issues: Too much UVB can lead to hypervitaminosis D, where the body produces excessive vitamin D³. This condition can cause calcium toxicity and other metabolic disorders, especially when using artificial lighting that lacks the natural UVA2 wavelengths (315-335 nm) that help regulate vitamin D³ production.

How do we stop a bearded dragon getting too much UV light? To prevent our bearded dragons getting too much UV we need to:

• Maintain a UVI of 3-7 in the basking area
• Always provide shaded retreats
• Create a UV gradient allowing self-regulation

Different morphs require different UV levels. Thin-scaled varieties like Silkbacks need lower UV intensities due to reduced natural UV protection from their scales.

Assuming the enclosure lighting and heating setup is right, then a bearded dragon will show when it’s getting too much UV by moving to shaded areas. This helps them regulate their UV exposure, just as they would in the wild.

Overexposure Risks	Underexposure Risks
Burns and Stress	Overly intense UVB exposure can cause burns and unnecessary stress, especially if your enclosure lacks shaded areas for your bearded dragon to retreat and self-regulate (Sakich & Tattersall, 2022).
Hypervitaminosis D	Artificial UVB lighting that omits key wavelengths, such as UVA2 (315–335 nm), can cause unregulated vitamin D3 production. This imbalance may lead to calcium toxicity and other metabolic disorders (Wunderlich et al., 2023).
Eye and Skin Damage	Prolonged exposure to poorly designed UVB-LED lamps, especially those emitting harmful UVC or non-terrestrial UVB, can lead to conditions such as photokeratitis, conjunctivitis, and skin thickening (Wunderlich et al., 2023; Sakich & Tattersall, 2022).

Impact of Scales on Bearded Dragons UV (e.g. Silkbacks)

Bearded dragons have evolved under the intense Australian sun, living in a full-spectrum light environment. However, selective breeding in captivity has changed the scale structure of some bearded dragons, affecting their natural UV protection. Here is how those scales make a difference:

Adaptation	Why It’s Important
Thick-scaled dragons (wild types)	Provide better natural UV protection, allowing them to tolerate higher UV intensities.
Thin-scaled dragons (Silkbacks, etc.)	Offer less natural UV protection, requiring lower UV intensities to avoid burns or stress.

Pro Tip: Watch your bearded dragon’s skin type and behavior. Thin-scaled varieties may bask less frequently or seek shade more often, signaling their need for lower UV intensities. Adjust their UV setup to meet their specific needs (Sakich & Tattersall, 2022).

The Bearded Dragon UV: Wrapping it Up

Our bearded dragons connection to UV light goes beyond a simple basking session—it’s the foundation of their health, happiness, and survival. Some of the things we uncovered were:

• UVA, UVB, visible light and infrared are non-negotiables: These bands work together like a power team, supporting everything from strong bones to active, curious behavior.
• Bearded dragons can get too much UV or too little: Bearded dragons are in danger of getting too much or too little UV.
• Bearded dragons know when they have had too much or too little UV: A safe and effective setup mimics their natural habitat, with UV gradients that let them regulate their own exposure.
• High-quality lighting is a must: Cutting corners with cheap, unsafe bulbs can lead to serious health risks. Lamps with improper ratios of UVA to visible light can distort how your bearded dragon perceives their environment. This imbalance may interfere with their ability to regulate UV exposure effectively (Wunderlich et al., 2023).
• Monitoring is essential: In the business world there is a saying “if you can’t measure it, you can’t improve it”. This is certainly true for providing UV for bearded dragons.

What gets measured gets managed.

Peter Drucker

A small adjustment today could make a world of difference for their tomorrow. 🌞 More bearded dragon health and wellbeing articles here.

References

• Baines, F. (2017). Your First Bearded Dragon Care Information.
• Divers, S. J., & Mader, D. R. (2006). Reptile Medicine and Surgery (2nd ed.). Elsevier Saunders.
• Mans, C., & Braun, J. (2014). Update on Common Nutritional Disorders of Captive Reptiles. Veterinary Clinics of North America: Exotic Animal Practice, 17(3), 369–395.
• Sakich, N. B., & Tattersall, G. J. (2022). Regulation of Exposure to Ultraviolet Light in Bearded Dragons (Pogona vitticeps) in Relation to Temperature and Scalation Phenotype. Ichthyology & Herpetology, 110(3).
• Wikipedia Contributors. (2019, January 23). Peter Drucker. Wikipedia; Wikimedia Foundation.
• Wilkinson, S. L. (2015). Reptile wellness management. Veterinary Clinics of North America: Exotic Animal Practice, 18(2), 281–304.
• Wunderlich, S., Griffiths, T. C., & Baines, F. M. (2023). UVB‐emitting LEDs for reptile lighting: Identifying the risks of nonsolar UV spectra. Zoo Biology.