UVB for Veiled Chameleons: How Long and How Far?
Veiled chameleons (Chamaeleo calyptratus) need substantial UVB exposure to synthesize vitamin D3 and process calcium properly, yet the right dose is often poorly calibrated in captivity. A study by Gary Ferguson and colleagues, published in 2010 in the journal Zoo Biology, measured the voluntary UVB exposure of several lizard and snake species in the wild to establish captive exposure benchmarks (study on Google Scholar). Our equipment comparisons are gathered in the reptile accessories section.
What distance between the lamp and the perch?
A veiled chameleon usually sits 8-12 inches below its UVB source, on the upper branches of its screen enclosure. Position the UVB tube or fixture at that distance from the main perch, never behind glass or fine mesh that would filter out much of the useful radiation. The cage model you choose directly affects this setup, as covered in our guide to screen cages for chameleons.
How many hours of exposure per day?
A 10 to 12 hour photoperiod mirrors the seasonal shifts this species experiences in the wild. Avoid a fixed cycle all year round: shortening it slightly in winter and lengthening it in spring tracks the animal's natural rhythm more closely, without ever cutting UVB entirely, even for juveniles. Hatchlings and growing juveniles are especially sensitive to underexposure, since their skeleton is forming fastest during that stage.
Is a combo tube or spot bulb enough?
Choosing the right equipment matters as much as getting the distance right, as covered in our guide to choosing a UVB lamp. A linear tube spanning the length of the main perch gives more even exposure than a single spot bulb, which creates a narrow, highly localized UVB zone. Whatever the model, output drops gradually well before the bulb stops looking bright, which is why a fixed replacement schedule matters.
Frequently asked questions
Can a chameleon get too much UVB?
Yes, excessive radiation with no way to move away from it can cause burns or photokeratitis; the animal should always be able to retreat out of direct range of the lamp.
Does glass block UVB?
Yes, ordinary glass blocks nearly all useful UVB, which is why a screen cage is used instead of a fully glazed terrarium or aquarium.
Is a calcium supplement still needed alongside UVB?
Yes, UVB enables vitamin D3 synthesis but doesn't replace regular calcium dusted onto feeder insects. Find all our guides on the reptile hub.
This guide is part of Planète Pets’s Reptiles universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.