Color-correcting glasses for working under LED grow lights. A full-spectrum panel throws a heavy magenta cast that makes true leaf color almost impossible to judge, which is how deficiencies and early pest damage get missed. These filter the light back towards neutral so you can inspect plants properly, and they cut the glare that leaves you with a headache after an hour in the tent.
LED light hides the symptoms you are looking for
Diagnosis is colour work. Nitrogen deficiency shows as yellowing on the older leaves, magnesium as yellowing between the veins, and a phosphorus problem as darkening and purpling on the new growth. Under a magenta LED all three look roughly the same, and so does the healthy plant beside them. The usual workaround is dragging a plant out of the tent to look at it in daylight, which is impractical in flower and impossible to do for every plant every day.
What the lenses correct
The tint cuts the excess red and blue that an LED panel puts out and passes what remains, which returns foliage to something close to its colour under daylight. It is not a perfect white balance, but it is enough to tell pale green from yellow, to see a leaf edge starting to burn, and to spot the stippling that means spider mites before the webbing appears.
Glare and eye strain over a long session
A modern LED board is bright enough that your eyes fight it the whole time you are working, and an hour of defoliating or tucking under one leaves most people with eye strain and a headache. Cutting the intensity means you can work at canopy height for as long as the job takes, and the things worth noticing are usually noticed in the last twenty minutes rather than the first.
When to wear them and when to take them off
Wear them for inspecting, training, defoliating and scouting for pests with the lights on. Take them off before photographing anything and before judging trichome colour, because the same tint that helps your eyes will skew both. For photographs, turning the panel off and using a neutral white light gives a truer result again.
