What is UV light?
UV light is an abbreviation for ultraviolet light, which has a wavelength of 400 – 10 nanometers, shorter than visible light. As far as reptile keeping is concerned, there are 3 types of UV light – UVA, UVB, and UVC.
UV light is naturally found in sunlight, and is the basis for life on earth. Organisms utilize UV light for photosynthesis, which makes up the base of most food chains on earth. The planet's ozone layer blocks almost 80% of the UV light emitted from the sun from reaching the planet's surface, mostly at the more harmful, shorter wavelengths. Still, we all have experienced UV light – that's what causes sunburns.