Wearing these Radians Flora Finders Glasses, you can see stressed plants, water-stressed turf, fire blight strikes and more. They're ideal for growers, consultants and field scouts. The special lenses block out green, which makes healthy plant material appear gray or black. Any other colors caused by drought, disease, poor nutrition or other harmful conditions stand out against this dark background. This allows you to see problems from far away. Glasses work best on sunny days with plenty of light to enhance the contrast.