Reptile Lighting Requirements


Do all reptiles need special lighting?  What light source is necessary for my pet bearded dragon?


Many reptiles have an absolute requirement for ultraviolet (UV) light, specifically in the b wavelength (UVB).  Bearded dragons are among the reptiles that have a very high requirement for UVB light.  Also on this list are iguanas, water dragons, uromastyx, chuckwallas, anoles, tegus, monitors, skinks, most varieties of turtle and tortoise, as well as many others.

Reptiles have adapted to use this light for a chemical reaction in their skin that helps them to maintain a normal calcium balance in the body.  Without UVB, many reptiles are unable to regulate their calcium and, over the long-term, end up with very weak and sometimes thickened bones, muscle tremors, and eventually die of complications (called metabolic bone disease).

Sources of UVB light include the sun and artificial sources such as mercury vapor bulbs and UVB producing fluorescent bulbs.  Generally, the sun and certain high quality mercury vapor bulbs are ideal for a pet bearded dragon.  Even the most powerful fluorescent UVB bulbs are only marginally acceptable, as they put out comparatively much less UVB wavelength light.  Keep in mind that the reptile must be able to get in direct contact with the UVB source.  Sunlight coming through a window or a UVB bulb with a plastic cover will not provide your pet with any useful beams.

UVB bulbs are available at most local pet stores.  It is best to have each bulb professionally tested shortly after purchase to ensure that it is actually producing appropriate levels of UVB.  You can’t always count on the label specifications, as some bulbs are poor performers.  The testing usually can be done (for a nominal fee) by a reptile veterinarian who is equipped with a UVB meter.  Each bulb should be tested every 6 months to make sure it is still effective.  Since UV light is not visible to the human eye, you will not be able to determine the efficacy of the bulb without testing it.  The particulars for your pet’s UVB setup should be discussed with your reptile vet as part of each annual wellness exam.


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Max Conn, DVM is the owner of Cat & Exotic Care of the CentralCoast, a full service veterinary hospital dedicated to the special needs of cats, birds, reptiles and small mammals.  Cat & Exotic Care is located in PismoCoastPlaza, 565 Five Cities Drive, 805-773-0228.  More information can be found at


Disclaimer: The informational handouts and website links above are for informational purposes only, they are not intended to replace veterinary care.