Part II: Right shades, right approach

Sight turfing, the systematic approach of daily observing the health of your field’s turfgrass, takes practice and patience. This allows you to adjust your treatment plans according to what the turf “tells you.” Read and react.

A high-quality pair of sunglasses is essential to the process. The right ones can condition outdoor light to your eyes’ preference and allow you to see through the green wash so you can stay a few steps ahead of plant stresses. Here’s what I look for:

  • Ultraviolet light protection – A must-have clear coating is applied to the lens that blocks almost all UVA and UVB light hitting the eyes. We often talk about skin protection from UV rays, but we rarely include a discussion about protecting our eyes. UV damage to eyes is cumulative over one’s life. Remember, UV protection is a clear coating and doesn’t have anything to do with how dark the lenses are.
  • Tint – Lenses are tinted to reduce the amount of light hitting the eye (lumens), and to filter down some colors (wavelengths). In some cases, certain colors are filtered out completely. The goal in sight turfing is to condition the light that hits the eye just right so that we can, with practice, learn to “hear” what the grass is “saying” through all the “noise.”

I like a medium tint. A tint that’s too dark or heavy makes it hard to see in the shade; too light a tint makes me go all “Popeye-eyed” when outdoors in bright sun. The color of the tint reflects how the sunglasses will filter certain wavelengths of light that enter the eye to various degrees. This is important to sight turfing. I keep a pair of yellow-tinted shades around for low light and foggy conditions. They really cut blue light down, bring the clarity up, and tend to “gather” light. Remember BluBlocker sunglasses? Various incarnations of these sunglasses have been around forever on TV infomercials. Things seem clearer when you filter down the blue light through these lenses. Blue light is easily scattered off almost everything. It scatters off the atmosphere and that’s why the sky is blue. Turns out, the BluBlocker-type sunglasses also tone the green down and make pretty good sight turfing glasses.

Regardless, the idea behind sight turfing is that you want to filter out mainly the green and blue light to some extent. These are castoffs and overload our rods and cones, making the non-green plant stress indicators harder to tease out. We don’t want to completely cancel out the green and blue light, just reduce it compared to the others.

If you’ve ever managed a grass field that’s seen on TV, you’ll think it looks much better on TV than live and in person. This is from all the green wash the cameras also get hit with. But now, with high-definition TV, the opposite is occurring, they are filtering out too much green wash, and the field tends to look worse than it does in person. This becomes real when an HD sky cam hovers over the middle of your football field for a team huddle late in the season with an audience of 55 million viewers. Seconds seem like hours to the sports field manager.

Maybe you’ve seen or tried the various purple plant-stress glasses that have come on the market over the last decade or so. These block out all the green light, they don’t just tone it down. Any healthy green tissue looks dark gray, and any part of the leaf that is showing stress is usually less dark or not dark at all, more of a tan color. The idea was developed by a NASA scientist, with the goal of making it easier to see camouflaged figures in the forest.

There hasn’t been much formal research on these, best I can tell. The National Forest Service did some work with them trying to see if they could document early tree stress detection by forest observers compared to no glasses and different sunglasses. Their conclusions, while a bit mixed, seem to mirror my experience with them. They are just another good tool, but not the be-all and end-all. They are crazy to wear, and some people even reported feeling disoriented wearing them. I agree that it takes a few minutes for the eyes to acclimate to them. It also takes practice.

They seem to work better in bright sun rather than in low light or shaded situations. They work best midday with a high sun angle, and are especially good for “wilt patrol.” They work better on fine turf than on a rougher looking, lower-input turf because the finer turf is generally more uniform, making it easier to observe differences.

They’re not designed to wear every day or even all day, and you definitely don’t want to drive in these, they cancel out traffic lights! Same with some of the BluBlocker-type sunglasses. Ever wonder why aviator’s sunglasses are usually green or gray? Green and gray-tinted lenses have the least amount of color distortion. As sight turfers, we do want to tone down the green and blue just right, but not make things so crazy we can’t wear them all day. Crazy lenses are great for a brief look or in unusual conditions, but your sight turfing sunglasses should be better suited for day-to-day wear. A rose-colored tint works best for me. It filters out just enough green and blue wash to let me see the real plant.

When it’s time to buy, there are a few other considerations for the sight turfer. You want sturdy sunglasses. Full frames are usually the strongest. Hand-ground lenses cost more, but are optically more correct. You don’t want distortion in your lenses with as much as you’ll be wearing them. Cheap lenses might even mess up your vision. At the store, put a pair on and look for any vertical line, the side of a cabinet for example. Keeping your sight trained on the vertical line, move your head side to side and see if there is any distortion. I don’t want too much color distortion either, just the right color conditioning. At the store I’ll find something red, something blue and something green to look at to evaluate any color distortion, and then I’ll take them out in bright sun and look at some green grass if possible to evaluate the tint.

Lens material on upper-end sunglasses is usually glass or polycarbonate. Glass usually costs a little more and can add weight, but it’s more scratch-resistant. Polycarbonate lenses may be optically less optimal, but they have a reputation of not splintering or shattering in case of an accident. While some occupational safety glasses are made of polycarbonate, never assume your sunglasses make appropriate safety glasses. Do your homework, and use the most appropriate OSHA-approved eye protection for the various tasks you might do.

Wrap-around sunglasses allow less glare in and are better for sight turfing. Polarized lenses greatly reduce or eliminate this. Always get polarized lenses. They can make it difficult to read LED screens at some angles, but it’s worth it.

High-quality sunglasses can cost as much as $150 to $250, but as a friend once told me “Buy the best, you only cry once.” My latest sight-turfing sunglasses cost $230, but I’ve had them eight years now, by far my personal record. Not a single scratch on my glass lenses. You can sometimes save big by going to the store and determining what you like best, and then shopping online for deals.

I always get a neck cord with my new glasses. As a sight turfer, you’ll be putting them on and taking them off 100 times a day probably. Setting them down or on your hat when not in use adds scratches and increases the chances you’ll break or lose them. The cord should have light rubber connectors that would easily break or pop off should your glasses get caught in anything. They’re cheap, so buy several. There are basically two kinds, side or end connecting, so find the type that’s most comfortable for you. It should be easy to pop them on and off all day long with one hand. In my turf office we always kept lens cleaning wipes available along with other safety products like safety glasses, sunblock and ear protection. Sight turfers need to keep their light conditioners clean.

Coming in June, Part 3: Let’s go Sight Turf!

Ross Kurcab, CSFM, is a Certified Sports Field Manager, consultant and owner of Championship Sports Turf Systems. He was the head turf manager for the NFL’s Denver Broncos for 30 years and holds a B.S. in landscape horticulture/turfgrass management from Colorado State University. You can reach him at