Natural sunlight has been scientifically proven to have good health benefits for birds, however that can be hard to do during the winter time with freezing temperatures, rain, and snow preventing us from taking our bird outdoors.
Some products promise a “full spectrum” of light, meaning they would produce UVB and UVA light, namely in spiral light bulbs. While this would be amazing, recent studies have shown that they do not deliver on these promises, and if used too close to your bird can cause cataracts and possible blindness. Check this video out for an explanation: https://www.breedingcage.com/.../full-spectrum-myth...
Light is still very important for birds to keep hormones in check, make food and toys seem more enticing, and much more, and lots of times the dim lights we use in rooms, or a window across the room just isn’t enough for them to see everything how they would in natural light.
We suggest using a good LED light as they are safe on our bird's eyes and do not need to be placed a certain distance away from them. The M&M Bird Cage Co. light that we carry provides a broader spectrum of visible light than most bulbs. They make lights for softbills such as canaries and finches and one for parrots which have chew guards over the lights and the cord is encased in aluminum to keep those beaks from chewing them up. (Still use caution with larger beaks like cockatoos and macaws as I am convinced they can find a way to break anything with those )