The following article brings to light one of the most commonly overlooked health risks facing indoor gardeners. Growroom operators are at an ever-increasing risk of permanent eye damage or even blindness due to rapid technological advancements in commercial- and industrial-grade lighting sources becoming ever more available to hobbyists and small-scale producers who are unfamiliar with the risks this high-tech equipment poses.

Horticultural lighting has come a long way over the last decade, graduating from those old, heavy-as-lead, magnetic, core-and-coil HPS and MH ballasts, to today’s lightweight and network-integrated “smart” electronic ballasts capable of automatically initiating sunrise/sunset fades and adjusting ignition times to avoid circuit overloads, among other things.

We have also seen major advancements in other lighting technologies, such as LED, plasma and electrodeless induction lights, bringing them into the indoor gardening and greenhouse industry. When it comes to grow lights, research and development focuses on two main factors: increasing energy efficiency and increasing PAR (photosynthetically active radiation).

Many of these optimizations have the unfortunate effect of exacerbating what are already extremely inhospitable environments for human health. The focus lighting manufacturers are placing on lower power consumption has no real bearing on growroom operator health for the most part, at least in regards to the dangers I am writing of, while their attention on PAR may need further explanation, as it has everything to do with the subject at hand. This is the specific field of advancement that is putting more and more people at risk of permanent eye damage, and even blindness.

PAR is the set of specific light-wave frequencies that trigger biological responses in plants such as phototropism, photomorphogenesis and photoperiodism. These biological responses affect the movement of a plant towards light, the regulation of growth, development and differentiation of plant tissues, and the regulation of the internal circadian clock, respectively. They also trigger photosynthesis, a plant’s ability to use light energy as a molecular building block to create new cells and grow.

Light waves come in a whole rainbow of frequencies, delineated by their specific wave patterns. Ultraviolet light has tiny wavelengths, and the farther up the electromagnetic spectrum you move, the larger the wave patterns become. Many of these wavelengths can have pronounced effects on physical matter, like radiation from nuclear waste, or X-rays at the doctor’s office. Even your microwave cooks food with wavelengths, which gives you an idea of how powerful they can be.

It turns out that the particular wavelengths that most advantageously affect plant growth are mainly grouped at the two opposing ends of our “visible” spectrum. Plants are most responsive to light waves in the red, blue, violet and ultraviolet ranges, and much less so in the middle of the visible spectrum, which is occupied by yellows and greens.

After years of research in this field, the inevitable happened, as it always must, and greater focus has been given to quantifying, isolating and reproducing each possible beneficial wavelength with the hopes of creating lighting sources that produce only the beneficial light waves and nothing extra, saving on energy that is normally wasted producing unnecessary frequencies and generating excess heat.

The most exciting development in this type of hyper-optimization of specific bandwidths for plant production is in the field of light-emitting diodes. LED lighting has had major boosts in power over the last few years, coupled with innovative optical lensing concepts to overcome earlier canopy penetration issues, finally making them a viable low-power option for plant lighting. In addition to the low heat generation benefits of LED lighting, it also allows us to have unprecedented control over the bandwidths of light we choose to create, giving us diodes that emit exact, nanometer-specific wavelengths for even greater energy savings than before.

Now here’s the rub—many, possibly even most, of these spectrums are exceptionally unhealthy for your eyes, causing a host of visual ailments that can lead not only to permanent eye damage, but could also even leave you blind. Some of the ocular maladies associated with these particular spectra include:

  • Macular degeneration: the leading cause of blindness
  • Cataracts: an unraveling of lens proteins that causes clouding within the lens
  • Pterygium: a growth on the whites of the eyes that can grow over the cornea
  • Pinguecula: another type of growth on the whites of the eyes
  • Photokeratitis: a painful but temporary corneal sunburn
  • Climatic droplet keratopathy: an accumulation of translucent proteins
  • Skin cancer: common around the skin of the eyelids after exposure to UV light

That’s a rather daunting list of ailments and injuries, to be sure—sure enough to fuel $36 billion in sunglasses sales in 2015, with an estimated rise to more than $56 billion dollars by the year 2020. With this enormous industry already in place, shielding the world’s vision from the evils of the sun’s harmful radiation, you would think we would be well-covered in terms of protection for those exposed to UV rays, but you would be wrong. Not only is the indoor gardener still at risk for eye damage, but they are exposed to even greater risks because of the nature of this type of commercial lighting.

Sunglass manufacturers offer us exceptional protection from not only light intensity, but also those pesky UV-A and UV-B rays—those UV light waves between 280 and 380 nm you hear so much about—but have you ever heard about UV-C? Probably not, because UV-C wavelengths, which are between 200 and 280 nm, are filtered out of our earthbound existence by the upper atmosphere. So, unless you design materials for spacecraft, are a welder, work with UV-germicidal apparatuses, or a few other specialized industry applications, you are not likely to ever encounter these kind of light waves as you go about your everyday lives. Except if you are an indoor gardener.

Today’s state-of-the-art horticultural LED lighting, regardless of the manufacturer, is probably rich in all bandwidths of UV radiation, requiring specialized eye protection inclusive of UV-C filtration as well as the standard UV-A and UV-B. There are hundreds of producers of UV-protective eyewear out there, and thousands of product offerings that will effectively shield your eyes from these dangerous light waves.

The downside of this is that they are designed for people in relatively standard work environments in regards to overall lighting, so they all come with clear or standard-tinted lenses, which will not color-correct the vision of the grower working under the overwhelming magenta glare of most horticultural LED lighting sources.

Why does this matter? Because all of these wonderfully dynamic wavelengths we have been discussing broadcast the most overwhelmingly magenta illumination you have ever seen. These lights create an environment that is mind-bendingly purple/pink—so much so that you lose all ability of color differentiation, which is the indoor grower’s No. 1 tool.

Visual inspection is the primary indicator of problems in regards to plant production; it is how we identify nutritional deficiencies, spot infestations or detect fungal infections. LED grow lights can be so intense that you not only lose all color acuity, but even your motion-detection abilities are hampered, especially in regards to minute objects, such as mites, thrips and gnats.

Unfortunately, there are precious few sources for eyewear specifically designed to block all three flavors of UV radiation while color-balancing the magenta illumination. But, at least there are few. Some pointers to keep in mind while shopping around? Top pricing does not mean top protection, but low pricing may be indicative of subpar materials incapable of proper three-band UV filtration or displaying poor color-balancing capabilities.

When researching potential growroom glasses, focus on products with the maximum amount of UV protection, not the coolest-looking style. Remember, these are for the growroom, where you are probably working alone. Choose the style that best blocks any light from getting to your eyes from around the frames. You want all the light to be passing through the lens of the glasses before striking your pupil. There are studies that prove a large amount of ocular damage is caused by UV light reflected off the backside of poorly fit UV-blocking glasses.

Once you have found some suitable protective eyewear, do yourself a favor and purchase an extra pair. Keep the extra set on hand for whenever you need a second pair of helping hands in the growroom, or for when you accidentally leave your primary pair at home because they were on top of your head when you left the grow.

Keep your protective eyewear hanging next to the entrance to your room so you always know where they are, and remember that they don’t do any good on a shelf or a hook, so be sure to put them on each and every time your eyes are exposed to the LED-illuminated environment.

A quote of paramount relevance, even as grossly out of context as it may be, seems appropriate for the closing paragraph of this PSA. We are left with these words, amongst many other things, from the illustrious botanist and inventor George Washington Carver: “Where there is no vision, there is no hope.”