Lighting: photo-kerato-conjunctivitis (UVB sickness)

[Morphius]

Photokeratoconjunctivitis (a.k.a UVB Sickness)
Symtoms: Swollen eyes, not opening eyes, inactive, not basking, not feeding.
Cause: Over exposure to high levels of Ultra-Violet Light

(Note: I already know many may disagree with what I am about to mention here)

I have found very little information regarding UVB Sickness here...or on the web in general as most seem to make assumptions about lighting...Repti-Glo versus ReptiSun brands are an excellent example of this. Someone comes onto the forum complaining about their beardie not acting normal or swollen eyes and we all shout "change the light!" when we learn it is a Repti-Glo. But do we have this advice wrong?

I have spent considerable time over the last couple days pouring over reptile light and light needs research and found two important pieces of information.

1) In 2007, UV Guide UK published a detailed report on the major reptile lighting brands.
2) After the report was published, most of these brands either stopped producing a particular bulb or replaced their bulbs with better ones.

Since the 2007 report, there has been no major study comparing the different light brands currently on the market which has been able to officially suggest that any of the current brands are better or worse than the other...however what is most commonly seen is talk and studies regarding the actual distance of the bulb in relation to the reptile.

UVB Filters?
We all know (of should know) that glass filters out most UVB, but did you know that if your enclosure makes use of a top mounted screen AND your UVB light sits above that screen, then up to 50% of the UVB light is not making it into the enclosure? It's true.

Distance is the Difference
I spoke to a guy 4 days ago who has two Bearded Dragon's aged 8 and 9 years old. He has been using Repti-Glo 10.0 for a couple of years now and has seen no ill effects in his beardies. When I went over to check out his setup, I noticed the tube lights were mounted about 10 inches away from the basking point (which was also the highest point in the enclosure). Both his beardies appeared in very good health and were very active...and yet, Repti-Glo is supposed to be a bad product. This lead me to question "so what are we missing?"

As it turns out, and not surprising at all, that not all lights are meant for all reptiles (clearly). But talk to most veterinarians OR look for actual independent reviews and you will find that Repti-Glo 10 and ReptiSun 10 are the two most suggested lights for Bearded Dragons, with preference to either really boiling down to cost and availability. However, where the difference between these two becomes clear is when you ask "how far should these lights be mounted from my pet?"

It seems the most common mistake made is to mount these fluorescent lights directly on top of the enclosure right beside the heat lamp or heat emitter. That in itself is not the actual mistake, but we then build a basking spot which can come within 6 inches of both lights...and THAT is the real mistake.

Like heat, which decreases the further you get from the source, so to does UVB strength decrease with distance, while getting closer to the source increases intensity. Meaning, allowing your Bearded Dragon to get within 6-8 inches of the UVB light source could be given it deadly amounts of light radiation.

Both the ReptiSun 10 and Repti-Glo 10 are recommended to be placed no less than 10-12 inches away from the basking point (or 20 inches away from the bottom of the enclosure) and ONLY recommended for enclosures 18 inches or taller in height. Both manufacturers also warn about the "burn-in" duration of fluorescent lights. The "burn-in" time is the first two weeks (or 170 hours) that the light is in use where the gasses and coatings are (for lack of a better term) warming up for long usage. During this time, the lights produce elevated UVB levels and it is recommended to mount both lights up to 20 inches away from the basking spot.

Bearded Dragons absolutely require a UVB gradient (same as a heat gradient) which is not properly accomplished by simply providing a hiding space. Most have the UVB light mounted at the same level for the full length of the enclosure which apparently does not provide a proper UVB gradient unless they also provide multiple shaded spots where light can still get through. This means the UVB lighting needs to be mounted on an angle so that the beardie (who has the ability to determine their own UVB needs) can move into or out of the effective UVB zone OR the enclosure needs multiple elevation levels with the lowest level being outside of the UVB effective zone. Since both the brands of lighting are rated to 20 inches of distance, this means that the furthest point in the enclosure needs to be at least this much...thus a 24 inch high enclosure (with the lights mounted directly on top) would be best suited for these lights, with the heat light or emitter mounted inside the enclosure about half way in (with protection to prevent contact).

Keep in mind this is not my opinion, but rather a summary of all the information I have been able to pull together (to the best of my uneducated capacity) but it seems to me that we are largely lacking up-to-date information currently about lighting and in desperate need of clarification.

Most reported cases of UVB sickness today apparently have little to do with lighting brand and more to do with having the UVB light to close to the beardie OR not following the directions of the bulb (especially during the burn-in period).

The "compact light" thread written in Aug. 2009 is GREAT! But what about the tubes?

Does anyone have any solid information regarding lighting (such as more recent studies) to support why we consider Repti-Glo "bad" and ReptiSun "good" or are we all simply believing urban legends because we didn't follow the instructions and our beardie suffered from UVB sickness?

 

[gearbox1001]

First i would like to give you a pat on the back for your research and pulling a debate around such a touchy subject. I think you have some point's but the main point in which comes from your analysis is the lack of up-to-date research on the actual bulbs in question.

This research is surly down to the manufacturer, has the manufacture got any statement's on how they feel their product is viewed by the customers they are tying to sell it too.?

Anyway, i enjoyed reading it
John

 

[Smid]

Good job on all the research!! :study: :study: I'm considering building a new enclosure (Smid! is spoiled as he already has a 4x2x1.5 but it is while melamine and not the nicest to look at) and am considering inside lighting - and to use the mega-ray would increase the size needed to hide the light. So thank you for your work and I hope we get some more answers on the lights since 2007!!

 

[Morphius]

First i would like to give you a pat on the back for your research and pulling a debate around such a touchy subject. I think you have some point's but the main point in which comes from your analysis is the lack of up-to-date research on the actual bulbs in question.

This research is surly down to the manufacturer, has the manufacture got any statement's on how they feel their product is viewed by the customers they are tying to sell it too.?

Anyway, i enjoyed reading it
John

The manufactures all feel their product is the best...which does us no good. I was even able to find reptile vets who also sat on both sides of the fence swearing Repti-Glo or ReptiSun was better than the other...but nothing to prove why?

What I have gathered though is that beardie owners should ABSOLUTELY get themselves a UVB reader to ensure that the UVB reading is between 290 - 300 (this is the range in which Vit D3 is produced) at the basking spot (which should be the highest point in the enclosure) which will allow you to properly distance the light from your beardie and ensure that everywhere else in the enclosure is providing less UVB exposure.

Again though, I am NOT an expert in lighting or in UVB or in Vit D3 production in reptiles and would love someone with more knowledge to weigh in on this subject.

EDIT Zoo Med (maker of ReptiSun) does not even recommend fluorescent lighting or heat lighting for a Bearded Dragon enclosure. Zoo Med's recommended enclosure setup uses a ceramic heat emitter and an MVB for the UV needs of the dragon.

 

[contessa20]

This is great information. Thank you for posting it.

I guess my question then is, if it is in fact the bulb distance rather than the brand then why are there so many reports of reptiles recovering with the only change in habitat being the bulb brand?

 

[Morphius]

This is great information. Thank you for posting it.

I guess my question then is, if it is in fact the bulb distance rather than the brand then why are there so many reports of reptiles recovering with the only change in habitat being the bulb brand?

And this is why we need more up-to-date information. Is this a case of "bad design" or is it a case of "bad human"?

If I buy a bulb which is designed to be say 15 inches from the reptile at the closest point, but instead I mount the bulb directly on top of an 18 inch high enclosure and build the basking point only 6 inches from the bulb, then what is actually causing the animal to get sick? The bulb or me? Then let's say I replace the bulb with one rated to be placed within 8-10 inches from the reptile at the closest point (thus I change nothing else in the enclosure), now what happens? The dragon gets better and I assume the problem was the bulb.

Right now, we assume the problem is the bulb, but is it? We know there was an issue with bulb design in 2007 and that many manufacturers changed their bulb designs since then...but what about today? And...how many people directly mount their lights onto the top of the enclosure and have enclosures 18 inches in height or less who come here and report problems regarding UVB sickness? Some of these bulbs are rated up to 20 inches! Meaning an 18 inch high enclosure receives almost no UV gradient at all!!!

This is why we need more information. If the problem is in fact a particular bulb brand, then action needs to be started to have this removed from the market because it would be hurting/killing thousands of reptiles all over the world...something which I highly doubt the manufacturer (Exo-Terra in this instance) intended to do given the amount of PR they spend money on to show how animal friendly they are.

 

[gearbox1001]

I also like to add that in the United Kingdom the manufacture's would be held to account if this was proven beyond doubt. Plenty of pet products have been removed due to the law because of fears of safety.

I also know on good authority (someone who works in the industry) that in the UK any dog food made is at a higher grade than human because if one pet gets ill and die's the company would be in serious do do.

So i know thats a different case in America, but it only takes some research and a platform to make an impact, if the light is safe then people need educating on how to use it correctly.

John

 

[Drache613]

Hello,

While I will agree, to a point, that there is "not much difference" between the Reptiglo & the Reptisun as they are both florescent tube bulbs. However, after the Reptiglo 8 was somewhat discontinued, the latest model of Reptiglo which is the 10, was a disaster on a lot of counts. I don't know whether you were aware of the differences of the Reptiglo 10 & the Reptisun 10 now or not, but I will tell you a little about them as of late. The Reptisun 10 florescent tube bulb has not had problems with any low wavelength production of UVB light, that is any wavelength below 285-290, & produces all quality high wavelength for peak D3 production. It can safely be placed at 6-10 inches from the reptile, AS LONG AS there is adequate bright white light directly beside it to protect the pupil from UVB emissions. This goes along with any UVB light placed in a tank of artificial creation though, there absolutely has to be enough bright white light for them for various reasons.
The latest model of the Reptiglo 10 florescent tube bulb had "some" lower wavelength UVB below 290 which was nonterrestrial UVB light which as you know can cause terrible problems & not just with the eyes. They had apparently used the incorrect phototherapy phosphor along with the wrong glass which the coating was too thin allowing the improper wavelength of UVB light to leak through.
On other notes, this light on appearance is actually "stronger" than the Reptisun 10. However, that can be misinterpreted. Stronger in this case, is NOT better. The lower wavelengths are not conducive to D3 synthesis, thus, that can really cause some calcium problems especially in the younger & growing dragons who need calcium for bone production, & strength. The reason we were seeing a lot of eye issues was for several reasons. The burn in time did not really have a whole lot to do with the problems, but the type of wavelength that was being produced. Sure, some were mounted too close, without adequate bright white light which definitely was a major culprit in some cases. However, in quite a few cases the lights were mounted at the proper distances, & some even further which basically were giving them not nearly enough of the needed UVB exposure. They were getting strong light, but not the right kind of strong light. The correct wavelength for PEAK D3 synthesis is 290-315nm but the PEAK is actually 297nm.
It is currently under review right now and should soon be included in the most recent UK UV guide review that is a compilation of UVB meter tests done on a yearly basis. So, there is a current study always going on, you just have to know where to find the information. I can direct you to more information so you can read, & keep up on some of it if you would like that is not a problem.
Now, as to why your friends' dragons of 8 & 9 years old "appear" to be healthy, that might be an illusion to some extent. Why some appear to have no ill affects when using a weaker bulb I don't know. Perhaps they had better lighting early on in life which helped them lay down a decent amount of bone mass while they were growing. They are hardy animals & can withstand bad husbandry to an extent. They can maintain their 25 hydroxy levels on minimum UVB exposure, but only for so long until their bone integrity may begin to suffer, over time. The only way you can really "see" the bone density is to get x-rays done on them, & then compare them to x-rays in which the bone mass was at least 1+ on the scale of density readings. There is a huge difference in x-rays of bones that are just "ok" & bones that are healthy. The appearance is astounding actually. If there bones are healthy they will be a very bright white, & if they are low in calcium, they are not very bright.
We have seen numerous cases in which people on here as well as other forums, etc, were using a Reptiglo 10 florescent tube or coil on their baby dragons. Quite a few of them fell prey to early symptoms of Metabolic Bone Disease. Most likely because the UVB exposure was not nearly enough for a growing dragon. They were unable to absorb calcium properly underneath this light.
As far as needing UVB, yes they most certainly do though a lot of people still try to get by without it. Sure they can somewhat survive without it, but there are not many exceptions to that rule. They bask for long periods in the wild under the intense sun, so providing that for them in captivity is the best. I am not a huge fan of florescent tubes, either. The Reptisun 10 & the Arcadia bulbs are very good. Bearded dragons have a very high requirement for UVB exposure. One of the main reasons is due to their thick armor of scales in which they don't really absorb much more than 3-4% of UVB through their backs. Most of the absorbption of UVB happens through their necks, & belly areas where the scales are minimal & more easily penetrated with UVB exposure.


Try reading on this site here:
http://www.uvguide.co.uk/index.htm


I will be happy to discuss lighting in more depth with you, if you have any further questions.


Tracie

 

[Drache613]

Moved by Moderator from Health to Enclosures

 

[Morphius]

Okay so the UVC leak you mentioned of, was also mentioned in the 2007 UV Guide UK....supposedly a issue fixed with the new Repti-Glo bulbs that are on the market now.

But having said that, if there are this many issues with fluorescents in general, then why use them? It does not seem to make sense to use something which has an extensive history of issues simply to save a few dollars in energy costs.

Also, unless I am looking in the wrong place, I cannot find any data on linear fluorescents later than 2007.

Also you bring up a great point regarding how they absorb UVB, being through their neck and belly area, which is why the basking spot should have a incline and not be horizontal (which is best for heat absorption).

Ultimately though...again this comes down to education and if MVB's are the best way to go (as you mentioned you are not a fan of them), then this is what we should be educating people on. I am though most interested in having further discussion regarding this issue as I believe it is a serious one.

 

[contessa20]

If I buy a bulb which is designed to be say 15 inches from the reptile at the closest point, but instead I mount the bulb directly on top of an 18 inch high enclosure and build the basking point only 6 inches from the bulb, then what is actually causing the animal to get sick? The bulb or me? Then let's say I replace the bulb with one rated to be placed within 8-10 inches from the reptile at the closest point (thus I change nothing else in the enclosure), now what happens? The dragon gets better and I assume the problem was the bulb.

Ahhh... okay, I see what you mean here and if that is indeed the case then you make a good point.

 

[Morphius]

I guess my point to all of this is (and it's not to ruffle any feathers or spread misinformation), but there are a LOT of lighting options with a LOT of opinions around them...

1) Linear Fluorescent
2) Compact Fluorescent (CFs)
3) Mercury Vapor Bulbs (MVB)
4) Halogen Bulbs (a.k.a Flood Lights)
5) Incandescent (old style household light bulbs)
-------a. Clear Bulbs
-------b. Colored Bulbs
6) Metal Halide

So the question quite simply is this, if a Bearded Dragon will be mostly enclosed in an area where they are mostly receiving artificial light, then as responsible reptile owners, what lighting should be used? What is the correct way to set it up (distances, enclosure sizes, etc)? How is it maintained?

If the only negative aspect of what "is the best to use" is ridiculous costs or availability, then what is the second best? We all "love" ReptiSun fluorescent lights and yet the supplier (Zoo Med) actually recommends using MVB for dragons...so maybe the advice we should be giving is "don't use fluorescent lights, it's not recommended". Because in my opinion, if we're not using the 1st or 2nd best options if they are available for use...then we really should not be owning these types of pets.

 

[Drache613]

Hello,

To my knowledge, all of the old stock of Reptiglo 10's are not off the market so they have still been sold at various stores. They never did jank them all off of the shelves, unfortunately. Frances is still working on her report for the Reptiglo 10 & until it is reviewed by Hagen company, she cannot release the test results for public view. So, that is where they are with that lighting report. Things take time.
I only recommend Mercury vapor bulbs. However, not everyone has a tank that is suitable for use of one. There are parameters in which they cannot be used, such as smaller tanks, short tanks, etc, for safety & ventilation purposes.
The compact/coil lights were off to a terrible start, & still are not the greatest. Frances has states her opinion & knowledge on them. She uses them only for geckos that do not have high UVB requirements. I personally do not feel that the UVB emissions are near enough for bearded dragons that have a very high UVB requirement. They can be pretty glaring on the eyes, as well, especially if bright white light is not being used enough.
The florescents are ok, because they do serve a purpose & if they are kept up by being changed out on a routine basis, the UVB emissions are quality enough to at least maintain bone health. That is the key, changing the tube light out every 5-6 months to maintain the higher UVB emissions. If they are not changed out routinely, the UVB output greatly decreases.
Halogen bulbs & household lightbulbs either one are great for basking lights. Halogens tend to run really hot, but, they are very bright. So, when using them caution must be used & a ceramic base light fixture should be used for it so it doesn't melt a plastic light fixture.
Colored lighting really has very little place in keeping reptiles. They do not do well under colored lighting. They are not bright enough to stimulate behavior, feeding, breeding, or to protect the pupil from UVB exposure. The bright white light stimulates activity, & protects the pupil by causing constriction & letting less light in so the eyes do not get damaged. A dim light allows the pupil to remain dilated which will allow more UVB light in thus having a higher incidences of eyes being damaged.
Metal Halides have been discussed in the past on this forum as a good source of UVB. The old metal halides have a "small" amount of UVB output, but, so negligible that it is not worth mentioning. Recently, Bob Mac the inventor of Megaray, has designed a Metal halide that does have excellent UVB.

Setups are not hard to do. Simple common sense & keeping it basic is really the best. Out in the wild they don't have a lot of fancy equipment, so in captivity they don't need a lot of fancy decor, etc, either. As long as the basics are met, they should have optimal health. Educating people on why UVB is needed, what it does, the reasons they need optimal lighting/brightness in the tank will go a long way in helping people take better care of their dragons, or other reptiles. There are a lot of options, so you need to weigh everything out & choose what is best for your tank design, & size.

The UV UK guide report should be up pretty soon, which will be a rather extensive report from 2008-2009.


Tracie

 

[Smid]

Thanks for the clarifications Tracie! This is a hot topic, and I like seeing the reasons behind why everyone says light 'a' is good and light 'b' is bad. In my mind it makes the decision that much easier because if you don't have the facts behind the statements it would be easier to say "what do they know" and go with the cheaper/easier option for you. The studies, reports and posts that informed (and trusted) people like yourself and Frances have contributed are greatly appreciated by myself (and Smid! and numerous others I'm sure). Thanks again for taking the time to explain some of this in a manner that is easy to understand for all. Thanks also to the original poster.

Liz

 

[Morphius]

I have to completely agree - this thread has gathered GREAT information which really goes a long way in making informed decisions regarding our pets. Definitely special thanks must go out to Francis and the folks at UV Guide UK as well as Tracie and the folks at thepats.info

So for me, since it appears MVB is the best way to go, what would be the proper MVB setup? What enclosure dimensions would I require? I just purchased a 48x18x24 size tank and will be preparing the setup this coming weekend. Would this be big enough to properly support an MVB setup?