Full spectrum light bulbs are designed to mimic the natural light spectrum. Unlike traditional bulbs, which emit a narrow and truncated light spectrum, full spectrum bulbs emit light across the entire visible spectrum. 

Some full spectrum bulbs (like those for reptiles) also extend into the UV range, while others (like incandescent and halogen bulbs) extend into the infrared (IR) range of light, but as a general rule, most full spectrum light bulbs contain a balanced and full visible light spectrum only, since a bulb with full UV, full visible, and full infrared light, is nearly impossible to achieve in an 'artificial' light source. Unless of course, you're talking about halogen or incandescent bulbs. 

Over the years, we've noticed some recurring questions popping up about full spectrum light bulbs in this business. Today, we'd like to answer your most common questions about full spectrum light bulbs. 

Question: Is a full spectrum light bulb the same as a daylight bulb? 

A: No, this is a common misconception. Full spectrum light bulbs have enhanced color rendering properties and a balanced visible light spectrum, similar to sunlight. Daylight bulbs do not necessarily mean full spectrum, but instead refer to light bulbs with a color temperature between 5000 and 6500K, the color temperature range of daylight at noon.

Question: Will a full spectrum light bulbs provide Vitamin D?

A: Most full spectrum light bulbs do not contain UVB light, which is necessary for the production of Vitamin D. Remember, most full spectrum light bulbs only contain the full spectrum of visible light. It is nearly impossible to have an artificial light source that contains a true full spectrum (UV, visible, and infrared) on its own. 

Question: Are full spectrum bulbs good for SAD? 

A: They won't hurt! While full spectrum light bulbs help those suffering from SAD, they are not considered a standalone treatment for seasonal depression. Light therapy boxes provide a much stronger light intensity and can be used only for about 30 minutes a day, while Chromalux® full spectrum lighting can be used without restrictions (like a standard light bulb). We answered this question in more detail. Read the differences between full spectrum light and light therapy.

Question: Are full spectrum bulbs the same as grow lights?

A: Not necessarily. Grow lights may have peaks of specific wavelengths necessary for plant growth (like enhanced blue or red light). In our experience, a grow light may not necessarily have a full spectrum of light, and they are not great for use as human lights!

Question: Are full spectrum lights bad for the eyes

A: Whether or not a full spectrum light is good for the eyes depends on two factors: light technology (incandescent, halogen, LED, fluorescent) and color temperature. The healthiest light for the eyes is the incandescent or halogen light bulb, or even better, Chromalux® incandescent light bulbs, which filter light uniquely and allow the eyes to relax.

Question: What are the best full spectrum light bulbs? 

A: The answer to this question is long-winded, and we've written more extensively about what we believe are the best full spectrum light bulbs here.

The answer is complicated because, apart from every one of us experiencing light differently, there is no uniform definition of what constitutes full spectrum lighting. Yes, full spectrum light (like sunlight) is any light that contains wavelengths of light spanning the entire electromagnetic spectrum of UV, visible, and infrared light. However, just one light bulb cannot contain true full spectrum light: full spectrum light bulbs include a full visible spectrum of light. Unless we're talking incandescent or halogen light bulbs, which have the most uniform visible spectral output plus infrared light, in any "artificial" light source.

But in a nutshell, the best full spectrum light bulb is the one that makes you feel best while accurately replicating some of the characteristics of natural sunlight: vivid colors, contrast, and that feeling of uplifted replenishment you get from the sun!