LEDBOKLI UV
LED LAMPREPORT
An investigation into an LED
Lamp from ShenZhen HengYi.

Thomas Griffiths, 2023
tom@tomaskas.co.uk
V 1.2.23

TABLE OF
CONTENTS
Disclaimer .................................................................................. 1

REASONS FOR TEST .................................................... 2
TERMINOLOGY USED .................................................. 4
Kit ............................................................................................. 4
Lamp/Unit .................................................................................. 4
Diode/LED .................................................................................. 5
UVI............................................................................................ 5
UVB ........................................................................................... 5
Ferguson Zone(s) ........................................................................ 6
Colour Temperature (and Corrected Colour Temperature)................. 6
Colour Rendering (Index)/CRI ....................................................... 7

TESTING METHODS..................................................... 8
Equipment .................................................................................. 8
Methods .................................................................................... 10

PRODUCTS TESTED ................................................... 11
LEDBOKLI Heating Lamp UVA+UVB LED ........................................ 11

INITIAL OBSERVATIONS .......................................... 12
Description and Build Quality ....................................................... 12
Box/Packaging ........................................................................... 13
Photographs .............................................................................. 14

UV PERFORMANCE .................................................... 17
IRRADIANCE CHARTS ............................................... 18
SPECTRAL MEASUREMENTS ...................................... 19
LED LAMP - 280 – 340nm ............................................................ 19
LED LAMP - 340 – 800nm ............................................................ 20
LED LAMP – Sunlight Comparison ................................................. 22

COLOUR MEASUREMENTS ......................................... 24
Overview ................................................................................... 24
Colour Values ............................................................................ 25

OTHER MEASUREMENTS ........................................... 27
Overview ................................................................................... 27

Measurments ............................................................................. 28
Light Category Breakdown ........................................................... 28
Relevant (D3) Action Spectra ....................................................... 28

COMMENTARY ON FINDINGS .................................... 29
Overall ...................................................................................... 29
UVI and UVB .............................................................................. 29
Spectrum and Vitamin D3 synthesis .............................................. 30
Colour Rendering and vision ........................................................ 31
Other Comments ........................................................................ 31

FURTHER TESTS........................................................ 32
Longevity and Degridation ........................................................... 32
Teardown .................................................................................. 32

SPECIAL THANKS ..................................................... 33
Colleagues ................................................................................. 33

LITERATURE AND FURTHER READING ...................... 34
Peer-Reviewed Literature ............................................................ 34
Other Literature ......................................................................... 37

DISCLAIMER
The content in this document including, but not limited to, the text,
graphics, images, links, and other materials is for informational
purposes only. The content is not intended to be a substitute forprofessional veterinary advice, diagnosis, or treatment, and does notconstitute as medical or other professional advice. Tomaskas Ltd. does
not recommend or endorse any specific tests, physicians, products,
procedures, opinions, or other information that may be mentioned inthis document, or on other company websites. Reliance on any
information provided herein is solely at your own risk. The information
provided in this document is designed to support, not replace, therelationship that exists between yourself and a veterinary surgeon.
Never disregard professional medical advice or delay in seeking it
because of something you have read in this document.
The details provided in this document are based on sole use, and the
document contains both scientific information as well as personal
opinion. Other people may have different results. The tests have been
performed to our best knowledge. Although, the tests do notsubstitute that of a laboratory test. There are uncontrollable variables
when testing a small batch of any item. Different items of the samemodel number may differ due to their manufacturing batch oroperating conditions.
This document may refer to the overall exotic animal keeping hobby as
the “reptile hobby”, but this is a force of habit – Tomaskas Ltd. does infact mean the keeping of the broader herpetological spectrum,including invertebrates, amphibians, and even birds.
Do not copy or distribute part or all of this document without explicit
written consent from Tomaskas Ltd. or the author. The author can becontacted by email at tom@tomaskas.co.uk.
Tomaskas Ltd. is registered in England and Wales with company
registration number 14112440.

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REASONS
FOR TEST

These tests were completed independently of ShenZhen HengYi
Technology Co., Ltd in China (ShenZhen HengYi).
ShenZhen HengYi is a company based in China, with a range of
products sold. They sell products for all different hobbies and interests– from lip gloss to desk fans - and don’t seem to be specialised in
reptile products exclusively.
The lamp tested here is marketed at use with reptiles.
The UK representative for ShenZhen HengYi is Evatost Consulting Ltd,apparently based in Wales, UK – however the company director has acorrespondence address in China, and the company address appears
to be a ‘virtual office’.
In order to provide the reptile hobby with a base understanding ofsuch products, it’s important that impartial tests are conducted. We
have a duty, as a community, to look out for each other and shareappropriate good practice.

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These tests aim to discover if products are suitable for the hobby,
independent of the manufacturer’s claims.
These tests aim to provide a better understanding of the products inquestion. The products are aimed at primarily providing a UVB and
UVA provision, but also acts as a source of visible light.
I have contacted ShenZhen HengYi on various occasions to offer
services of independent testing. I have received no correspondence
from them.
I decided to purchase the lamp myself as I wasn’t getting anywherewith ShenZhen HengYi.
I will let the reader come to their own conclusions about ShenZhen
HengYi’s lack of response or correspondence.

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TERMINOLOGYUSEDAs with many things, there may be more than one correct or colloquial
way to describe the same item. There may also be common terms
used that may not be correct in everyday usage. I’ve tried to remain
consistent throughout the document so that if I refer to a specific partof an item, you as the reader will know with confidence which part I’mreferring to. I’m only human though, and there may be mistakes.

KIT
This refers to everything that comes in the box, including fittings andinstructions.

LAMP/UNIT
This refers to the main item in the kit. It is a small E27 screw in unit.
Inside the lamp are electronics to ensure that the lamp turns on andworks as intended.

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DIODE/LED
The individual electronic parts that emit light (including UV).

UVIThis is shorthand for Ultra Violet Index. UVI is a standardised
measurement for the appropriate wavelengths of radiation associatedwith essential biological processes involving the synthesis of Vitamin
D3 – it is often used as a measure of solar UV radiation at the Earth’s
surface in terms of potential damage to the skin and the eye. The
higher the UVI, the less time it takes for harm to occur. This document
does not aim to educate about this biological process specifically, andfurther reading is readily available online. By continuing, it ispresumed that you have an understanding of UVI and its relevance tothese tests. UVI is not to be confused with UVB. UVI is not to be
confused with the Ferguson Zones.

UVB
UVB is the term for part of the electromagnetic spectrum on certain
wavelengths, generally between 280 and 320nm. This document does
not aim to educate about this specifically, and further reading isreadily available online. By continuing, it is presumed that you have an
understanding of UVB – including the differences between terrestrial(solar) UVB, which is around 295-320nm, and the more dangerous
non-terrestrial (non-solar) UVB, which is from 280nm to around
295nm.

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FERGUSON ZONE(S)The Ferguson Zones are classification markers for different exposurelevels to different UVI. There are 4 Zones. Animals that expose
themselves naturally to lower UVI are classified as Ferguson Zone 1,
and animals that naturally expose themselves to high UVI areclassified as Ferguson Zone 4. This document does not aim to educate
about this specifically, and further reading is readily available online.
By continuing, it is presumed that you have an understanding of
Ferguson Zones – including the differences between the different
Zones.

COLOUR TEMPERATURE (AND CORRECTED COLOURTEMPERATURE)
Colour temperature, or CT, is widely used to define the colour
appearance of a light source. Colour temperature is technically onlyused for “true” light sources – defined as a black body that reads closeenough to the Planckian locus.
Corrected Colour Temperature, or CCT, is used on a light source that
doesn’t read close to the Planckian locus.
Both are defined in degrees Kelvin where a Warm White is around2700K moving to Neutral White at around 4000K to Cool White, 5000K
or more. Note that Colour Temperature and CCT do not tell you
anything about the colour rendering ability of a light.
This document does not aim to educate about this specifically, andfurther reading is readily available online. By continuing, it ispresumed that you have an understanding of CT/CCT – including thedifferences and similarities.

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COLOUR RENDERING (INDEX)/CRI
Broadly defined as an indication of how well a light source can provide
wavelengths that allow for certain colours to be visible to the humaneye. This is defined by the CIE in greater detail, along withstandardisations on measuring the level of colour rendering capability– referred to as the “index” of colour rendering.
Light with a low CRI is less effective as one with a high CRI. The CRI of
unobstructed sunlight is 100.
This document does not aim to educate about this specifically, andfurther reading is readily available online. By continuing, it ispresumed that you have an understanding of CRI.

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TESTING
METHODSEQUIPMENT
In order to ensure that results are as true and comparable as possible,
I have used standardised measuring devices for the tests. I have useda SolarMeter 6.5 for measuring UVI, and a SolarMeter 6.2 formeasuring UV in µW/cm².
The spectral response of these broadband meters is shown below. On
these graphs, “Erythemal” refers to the action spectrum for the UV
Index, since this is derived directly from the action spectrum for skinreddening (“erythema”) under UVB.

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To allow for full spectrometry, a calibrated FLAME Spectrometer from
Ocean Optics was used alongside their flagship software – OceanView.
Room temperature measurements were taken with an Inkbird branded
digital thermometer, with part number IBS-TH2. The manufacturer
claims the device to have an accuracy of ±0.3°C.
A drywipe backboard was used for the “manual” portions of the tests.
The backboard was pre-marked with a grid pattern. The grid used is
2.5cm squares. The board is approx. 2mx2m in total. The board does
not reflect UV.
The distance from the unit was determined using a Stanley tapemeasure, with points marked on the backboard.
A Windows 10 PC with Microsoft Office and Adobe Photoshop CC 2015
was used to digitise the results and write up this report.
A power meter was used, model KWE-PM01, to monitor power usage.
A Dr Meter LX1330B was used to manually determine LUX values.
The lamp is 220-240V. I used a voltage transformer to correctly power
the lamp.
SCHOTT N-WG295 Long Pass Glass (WG295 Glass) was used whereappropriate to monitor for UVC vs noise on the spectrometer.

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METHODS
Precaution was taken with all tests, as there should be when dealing
with UVB-emitting devices. “Factor 50” UV protection sun cream wasused on skin, with care taken not to spread any onto the equipment orlamps.
The method for creating ISO Irradiance charts is very close to themethod documented by UV Guide. I have made comparisons with myresults and those of the UV Guide, and the results are withintolerances – this means that the results are comparable to those of the
UV Guide.
Info here: (http://www.uvguide.co.uk/makingspreadcharts.htm)
Before every test took place, a dry microfibre towel was used to wipe
the lamp to ensure that the lamp was clean.
UVI was measured in the testing room before each test to ensure that
results were only measuring the lamp and not any other sources.
Spectrometer readings were taken in line with standard processes.
The Reptile Lamp Database, courtesy of Dr. Sarina Wunderlich, wasutilised for some technical analysis.
The lamp was given 30 minutes to “warm up” before each individual
test, unless otherwise noted.
The lamp had 50 hours of “burn-in” before the tests began, unlessotherwise noted.

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PRODUCTSTESTEDThe following product was tested.

LEDBOKLI HEATING LAMP UVA+UVB LED
I tested one of these kits (n=1) in total. Model number is UK 5413254.
The product is very easy to find on Amazon UK when searching withterms such as “Reptile lamp”, “Reptile UVB”, “Tortoise lamp”, “Tortoise
UVB”, “UVB LED”, and “UVB lamp”. It is rated highly (average 4.3stars at time of writing) by users.

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INITIAL
OBSERVATIONSDESCRIPTION AND BUILD QUALITY
The kit contains two lamps and a clip-on goose-neck fixture with adimmable switch.
One of the lamps is an unprotected halogen lamp, which have beenshown to emit significant trace amounts of UVC. This lamp was nottested as this is a well-known phenomenon and is expected from aquartz-glass halogen lamp. The use of this halogen lamp is notrecommended.
The other lamp is an LED unit – and this is the primary focus of thetests.
The LED weighs approximately 50g, and feels solid.
The E27 screw fitting itself looks well made.
The face of the lamp appears poorly made – there is messy solder andthere are some solder burns visible. The diodes are protected by aglass shield.

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There is no writing on the lamp indicating any safety markings orvoltage.
Initially it appears that there are some non-light emitting diodes –there is a ring of 16 “white” diodes and a ring of 8 diodes that could be
UVB or UVA. This will be tested.

BOX/PACKAGING
The outer box of the kit shows the goose-neck clip and a small turtle
basking under the lamp. The images are clear, and there is no blurry
text.
There is a visual representation of a spectrum on one side of the box,
presumably from the LED lamp as it appears to be a typical LED
spectrum.
The main box shows safety markings for RoHS, FCC CE, and UKCA.
Inside this main box is another smaller box for the LED. This box has
blurry images and text. This box is green and pictures two small
turtles. The box states “Halogen Lamp UVB3.0”, even on the LED
product.
It is also made very clear on the box that there are 16x White (3000K)
diodes, and 8x UV diodes. The specification given is 97% UVA and 3%
UVB. This will be tested.
It claims to use 3.5W.

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PHOTOGRAPHS
Here are some images of the lamps and accessories etc. Descriptions
are provided where appropriate.

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Goose-neck fixture and dimmer switch. Not tested here.

Unprotected halogen. Not tested here as this kind of lamp has alreadybeen extensively tested by Dr Frances Baines and shown to be
dangerous.

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Box that contains the LED. Note that it states Halogen. Claims toreverse metabolic bone disease. Claims 3% UVB (out of UV emitted).

LED face. Notice the solder burns, cracked board, and spilled solder.

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UV
PERFORMANCE

There was no UVB detected, with either a Solarmeter 6.5 or
Solarmeter 6.2, throughout the burn-in period or after the burn-in
period of 50 hours.

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IRRADIANCE
CHARTS

No irradiance charts have been made, as there is no UVB to measure.

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SPECTRAL
MEASUREMENTS

LED LAMP - 280 – 340NM
Reading taken at 30cm away from the lamp. Lamp warm-up was 30
minutes. This reading was taken after the lamp had burned-in for 50
hours.

There is no UVB.

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LED LAMP - 340 – 800NM
Reading taken at 30cm away from the lamp. Lamp warm-up was 30
minutes. This reading was taken after the lamp had burned-in for 50
hours.

Full page graph is on the next page. Commentary is in a later section.

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LED LAMP – SUNLIGHT COMPARISON
The below chart shows the spectrum from the lamp to sunlight (ASTM
sunlight). The spectral plot of the lamp has been drastically up-scaled(to approx. lux 20,000) in order to be visually comparable to sunlightfor the sake of analysis.
Reading taken at 30cm away from the lamp. Lamp warm-up was 30
minutes. This reading was taken after the lamp had burned-in for 50
hours.

Graph made using Reptile Lamp Database Software, Courtesy of Dr. Sarina Wunderlich

Full page graph is on the next page. Commentary is in a later section.

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Graph made using Reptile Lamp Database Software, Courtesy of Dr. Sarina Wunderlich

tom@tomaskas.co.uk

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COLOURMEASUREMENTS

OVERVIEW
The spectrometer software is able to calculate colour values based on
the readings from the lamp.
The range of wavelengths used to generate these values is dictated by
the CIE. Their range defined is 400nm to 750nm.
These standards are defined as such for human vision only, and they
do not take into consideration reptile vision in the UVA range.
I have also used a slightly wider range (350nm to 850nm) to allow
analysis of typical reptile photoreceptor excitation by software.
Measurements taken using centre point of lamp at 30cm away, with all
diodes on.

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COLOUR VALUES
The lamp had its colour values checked. Data is below.
Category

25

Ref

Value

CCT (Kelvin)

3112K

CRI(a)

73.1

R1

71.4

R2

82.8

R3

89.8

R4

68.0

R5

70.0

R6

76.0

R7

76.8

R8

49.9

R9

-17.6

R10

58.0

R11

61.7

R12

56.5

R13

73.2

R14

93.5

R15

73.1

DC<5.4E-3

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tom@tomaskas.co.uk

Below is a chart showing excitation of the 3 “cone” visualphotoreceptors used in human vision, as they would be stimulated by
the spectrum on the platforms. The coloured vertical bars show thecone stimulation level; the short green horizontal bars show theequivalent stimulation by natural sunlight. The chart gives a visual
representation of how well colour is rendered by humans.

Graph made using Reptile Lamp Database Software, Courtesy of Dr. Sarina Wunderlich

Reptiles have different photoreceptors to humans. And most species
are also different to each other. This makes it difficult to quantify andanalyse light for reptile vision. Basic assumptions can be made though.
Below are the same charts showing excitation of the “3 cone” visualphotoreceptors used by some reptiles and birds (left), and the samefor “4 cone” visual photoreceptors used by other species of reptile andbirds (right), as they would be stimulated by the spectrum in thisenclosure. The coloured vertical bars show the cone stimulation level;
the short green horizontal bars show the equivalent stimulation by
natural sunlight. The chart gives a visual representation of how wellcolour is rendered by different species of reptile or bird.

Graph made using Reptile Lamp Database Software
Courtesy of Dr. Sarina Wunderlich

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Graph made using Reptile Lamp Database Software
Courtesy of Dr. Sarina Wunderlich

tom@tomaskas.co.uk

OTHERMEASUREMENTS

OVERVIEW
The spectrometer software is able to ascertain certain values based on
the readings from the lamp. Each reading was taken at 30cm whereappropriate. Readings taken after 50-hour burn-in. The lamp was
given 30 minutes to warm up before each test. I have listed theIlluminance (Lux), Luminous intensity (Candela), Power Density(µWatt/cm²), UVB density (250-320nm in µWatt/cm² using SolarMeter
6.2), UVI (SolarMeter 6.5), SolarMeter Ratio, Power Factor, andaverage wattage values. Integration began at 280nm and ended at
850nm for measurements, excluding the tests done with theSolarMeter 6.2 and SolarMeter 6.5. This encompasses the range of UV,Visible Light, and the very shortest Infrared Wavelengths. Simpson’srule was used for integration between 270 and 800nm.
This section also contains light category breakdown and action spectra
analysis.

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MEASURMENTS
The following are readings taken from the lamp after a 50-hour burnin period at 30cm.

Category

Lux

PDµW/cm²

Candela(SM6.2)
UVB(SM6.5)UVISM Ratio

Power
FactorAverage
Wattage

Voltage

Value

714

311.8

0.008538

0

0

0:0

0.56

3.6

236.5

LIGHT CATEGORY BREAKDOWN
The light from the lamp underneath the UVB-emitting diodes can be
broken down as follows. The measured range for these readings is
280nm to 780nm.
Grouping

W/m2

Percentage of total Measured Range

UVB (280-320nm)

0

0.00%

UVA (320-400nm)

0.288

9.24%

Visible (400-780nm)

2.83

90.76%Of the UV emitted (280-400nm), the breakdown is as follows:
Grouping

W/m2

Percentage of total Measured Range

UVB (280-320nm)

0

0.00%

UVA (320-400nm)

0.288

100%

RELEVANT (D3) ACTION SPECTRA
There is zero activity in the action spectra associated with D3
synthesis and regulation.

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COMMENTARYON FINDINGSOVERALL
The lamp worked without any faults during the tests. It did not get hot
during the test.
Despite the word “Halogen” on the box, the lamp is not a halogen
lamp.
The lamp used slightly more than the 3.5W as stated on the box.

UVI AND UVBThe UVB output from the non-existent. No matter how close an animal
is to this lamp, they will not be exposed to UVB.

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SPECTRUM AND VITAMIN D3 SYNTHESISThe spectrum measured from the lamp is very different to that on thebox.
From the data collected from the lamp, the following can be stated:
1. The lamp emits no UVB.
2. The lamp’s UVA output is minimal.
3. The lamp will have no effect on Vitamin D3 synthesis.
4. Using this lamp as a source of UVB is likely to lead to metabolicbone disease in an animal.

In practical terms, this tells us that the lamp does not do what it
claims on the box or in the marketing online.
Long term, an animal may develop metabolic bone disease due to thelack of UVB being emitted. It will certainly not reverse metabolic bonedisease as stated on the box. The lamp does not approximate sunlightin the UVB or UVA range at all.
The UVA emitted is minimal, as the “UVA” diodes peak at 400nm,
which is classified as violet and not UVA.
There is activity in the visual spectrum – typical of white LEDs. The
white LEDs clearly have a phosphor to allow a warm tone to them. This
is not out of the ordinary.

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COLOUR RENDERING AND VISION
The colour, to my eyes, is a “warm white”. The lamp renders colour forhuman vision poorly. To an animal, it can be presumed that the lamp
will not render colour very well at all.
The lamp is not very bright. But this is to be expected if considering
the fact that a number of the diodes are non-visual and are using up a
portion of the overall wattage.

OTHER COMMENTS
The Power Factor of the lamp is approximately 0.56. This is very low.
This is not atypical of an LED product.
There are no safety markings on the lamp, which concerns me as they
are for sale in the UK.
I am untrusting of the safety markings on the box. Perhaps these only
apply to the goose-neck fixture and not the lamps inside, I am notsure. Although the LED itself doesn’t appear to be dangerous (in thesense that it doesn’t emit dangerous wavelengths of light), it is notsuitable for use with animals as advertised.
Considering the findings, it is worrying to see a large number of 4- and5-star reviews on Amazon UK regarding this product – with somereviews titled “The perfect basking lamp” and “Great for African SpurThigh Tortoise”.
This document will be posted to the UK Rep
I do not recommend this lamp for use with animals. I recommend
anyone who has purchased this lamp to contact their seller andrequest a refund.

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FURTHER TESTSLONGEVITY AND DEGRIDATION
There is no statement that the lamp will last for any amount of time.
This was not tested, although such a test is doable if time was put
aside for the test.

TEARDOWN
At this point I have not conducted a teardown of the lamp. This could
involve reviewing electronics inside, although I may seek further
counsel on this first as I don’t want to break any laws regarding
intellectual property.
LEDs are widely used in many sectors, and I don’t suspect there is any
ground-breaking technology inside to warrant a teardown.

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SPECIAL
THANKSSpecial thanks are in order for many friends, colleagues, and partners.
I’d like to give a thank you to the following, but there are undoubtedly
more that have not been named.

COLLEAGUESDr Sarina Wunderlich has kindly allowed me to utilise her Reptile Lamp
Database system to generate some technical graphs and datasets. She
has not explicitly endorsed this document or seen it before release.
Dr Frances Baines has extensively studied unprotected halogen lamps
before, and is working to educate where possible about the dangers ofthese lamps when used with animals. She has not explicitly endorsed
this document or seen it before release.

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LITERATURE
AND FURTHERREADINGIn this paper, I have made comments supported by scientific
literature, both peer-reviewed and not. Here is a list of literature that I
have either directly referenced, or used in support of points and claims
that I’ve made. The list is not extensive.

PEER-REVIEWED LITERATURE
Holick, M. F (2016) - Biological Effects of Sunlight, Ultraviolet
Radiation, Visible Light, Infrared Radiation and Vitamin D for Health.
Anticancer Research 36: 1345-1356 (2016)
Wacker and Holick (2013) - Sunlight and Vitamin D.
Dermatoendocrinol. Jan 1; 5(1): 51–108.
Christopher J. Laing, Angelika Trube, Glenn M. Shea, and David R.
Fraser (2001) - The requirement for natural sunlight to prevent

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vitamin D deficiency in iguanian lizards. Journal of Zoo and Wildlife
Medicine 32(3), 342-348.
Acierno, M.J., Mithcell, M.A., Roundtree, M.K., and Zachariah, T.T.,(2006) - Effects of ultraviolet radiation on 25-hydroxyvitamin D3
synthesis in red-eared slider turtles (Trachemys scripta elegans).
American Journal of Veterinary Research, 67(12), pp. 2046-2049.
MacLaughlin, J., Anderson, R. & Holick, M. F. (1982) - Spectral
character of sunlight modulates photosynthesis of previtamin D3 andits photoisomers in human skin. Science, 216 1001–1003.
Baines, F. M. et al. (2016) - How much UV-B does my reptile need?
The UV-Tool, a guide to the selection of UV lighting for reptiles andamphibians in captivity. Journal of Zoo and Aquarium Research, 4.
Ferguson, G. W. et al. (2010) - Voluntary exposure of some westernhemisphere snake and lizard species to ultraviolet-B radiation in thefield: how much ultraviolet-B should a lizard or snake receive incaptivity? Zoo Biology 29(3), 317-34.
Scott, R. K. et al. (2015) - Evolutionary transformation of rod
photoreceptors in the all-cone retina of a diurnal garter snake. PNAS
113, 2.
Sillman et al. (1999) - The photoreceptors and visual pigments in theretina of a boid snake, the ball python (Python regius). The Journal of
Experimental Biology, 202, 1931–1938.
Kelber, A., Vorobyev, M. & Osorio, D. (2003) - Animal colour vision behavioural tests and physiological concepts. Biological Reviews, 78
81–118.
Katti C, Stacey-Solis M, Coronel-Rojas NA and Davies WIL (2019) The Diversity and Adaptive Evolution of Visual Photopigments in
Reptiles. Front. Ecol. Evol. 7:35.

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Sarika Paul and Timothy M Brown (2019) - Direct effects of the lightenvironment on daily neuroendocrine control. Journal of
Endocrinology, 243:1.
Albers et al. (2019) - Blue light (λ=453 nm) nitric oxide dependently
induces β-endorphin production of human skin keratinocytes in-vitro
and increases systemic βendorphin levels in humans in-vivo. Free
Radical Biology and Medicine 145 78-86.
Grace, Michael S. (1997) - The visual system and non-visualphotoreception. The Biology Husbandry, and Health Care of Reptiles.
Lowell Ackerman, DVM, ed. Vol. I, pp. 325-341.
G. Chen et al. (2017) - Mercury speciation by differential
photochemical vapor generation at UV-B vs. UV-C wavelength.
Spectrochimica Acta Part B 137, 1–7.
C. M. Lerche et al. (2017) - UVR: sun, lamps, pigmentation andvitamin D. Photochem. Photobiol. Sci., 2017, 16, 291-301
Lindgren, J., Gehrmann, W. H., Ferguson, G. W. & Pinder, J. E. (2008)- Measuring Effective Vitamin D3-Producing Ultraviolet B Radiation
Using Solartech’s Solarmeter® 6.4 Handheld, UVB Radiometer.
Bulletin of the Chicago Herpetological Society, 43 57–62.
Holick, M. F. (2016) - Biological Effects of Sunlight, Ultraviolet
Radiation, Visible Light, Infrared Radiation and Vitamin D for Health.
Anticancer Research, 36 1345–1356.
James K. Bowmaker (2012) - Evolution of the Vertebrate Eye. How
Animals See the World: Comparative Behavior, Biology, and Evolutionof Vision 23 441–472.
Tosini et al. (2001) - The circadian system of reptiles: amultioscillatory and multiphotoreceptive system. Physiology &Behavior 72 (2001) 461-471.

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Kalajian, T. A., Aldoukhi, A., Veronikis, T.J., Persons, K.& Holick, M. F.
(2017) - Ultraviolet B Light Emitting Diodes (LEDs) Are More Efficientand Effective in Producing Vitamin D3 in Human Skin Compared to
Natural Sunlight. Scientific Reports, 7 11489.
Sakich and Tattersall (2022) - Regulation of Exposure to Ultraviolet
Light in Bearded Dragons (Pogona vitticeps) in Relation to
Temperature and Scalation Phenotype. Ichthyology & Herpetology
110, No. 3, 2022, 477–488.
Cusack, L., Rivera, S., Lock, B., Benboe, D., Brothers, D. & Divers, S.
(2017) - Effects of a light-emitting diode on the production ofcholecalciferol and associated blood parameters in the bearded dragon(pogona vitticeps). Journal of zoo and wildlife medicine, 48 1120–
1126.

OTHER LITERATURE
Sinclair, Sandra (1985) - How Animals See: Other Visions of Our
World. Croom Helm, London.
Dr Frances M Baines (2021) - Vitamin D3 Synthesis: A self-limiting
process in natural sunlight.
Loos, B. de (Babette) (2016) – Production of cutaneous vitamin D3
after UVB radiation in reptiles and amphibians. Faculty of Veterinary
Medicine Research Internship Department: Biochemistry and Cell
Biology
GOV . UK (2023) – Guidance - Using the UKCA marking.
GOV . UK (2023) – Guidance - Using the CE marking.

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