Takeaway: With constant technological advancement in horticultural light systems, indoor growers who choose LED lights may be able to calculate higher yields for their plants in shorter amounts of time. But scientific breakthroughs benefitting the growth of your plants might pose unseeable risks to your eye health, especially long term.
Most grow lights on the market are manufactured for specific wavelengths targeting different stages of plant growth: red Light Emitting Diodes (LEDs) activate seed, root, flower and fruit production; blue LEDs make strong stems and roots; and both have a strong role in active photosynthesis. On the other hand, plants also need yellow light, like that produced by High Pressure Sodium (HPS) fixtures, for photorespiration, or the growth stage where plants consume most of their nutrients. Though many growers use HPS and other combinations of light sources successfully, new full-spectrum LEDs are becoming more available as an energy-efficient and economical choice for high-yield grows.
Full-spectrum LEDs and UV radiation
Why should growers consider full-spectrum LEDs? LEDs utilizing the full light spectrum replicate the effects of natural sunlight more closely than other artificial light sources. When the entire light spectrum is available to plants, they can differentiate between each targeted light spectrums, which we see as colors, for higher absorption and cellular activation. The full spectrum that includes rays both visible and invisible to the human eye appear white in color when active simultaneously. Though the white, sun-like conditions make it easier to see normal colors with the naked eye (as opposed to traditional LEDs that appear pink or purple, or HPS lights that appear yellow), the highest risks of eye and skin damage exist in the invisible UV rays emitted by these lights. Later, we’ll mention the potential risk of visible blue light that’s also present in these types of fixtures.
Any artificial light used for indoor growing emits a certain amount of UV-A and UV-B Radiation by default, since these rays are what contribute to photosynthesis in natural sunlight. Almost anyone who’s ever worn sunblock is familiar with UV-A and UV-B, the most well-known types of UV radiation emitted by the sun. A third type of UV Radiation, UV-C, is also present in natural light but is almost 100 per cent absorbed by the Earth’s atmosphere. With artificial light, particularly full-spectrum LEDs, there is a high probability of UV-A and UV-B Radiation, but also potential exposure to UV-C Radiation, which poses the most serious risks to eye and skin health
