Red light is safe for your eyes, and so is near-infrared from therapy lamps. The persistent warning that infrared light harms the eyes is true, but it is about a completely different kind of source than a red light therapy LED panel.
Red light is not UV
Eye damage from light is first of all a question of wavelength. Ultraviolet light carries enough energy per photon to break molecules in the cornea and lens. That is photochemical damage, and it adds up over time. Red light at 660 nm and near-infrared at 850 nm sit at the other end of the spectrum, with far less energy per photon. That mechanism does not apply there.
Where the warning about infrared comes from
From heavy industry. Glassblowers and steelworkers who stood right in front of molten glass or steel for hours a day, for years, developed cataracts noticeably more often. Lydahl described this in two epidemiological studies in 1984. That is a thermal effect from extremely powerful infrared sources over an entire working life. Ten minutes in front of a red light therapy panel is a different order of magnitude.
What does count: you cannot see 850 nm. You do not blink at it and your pupil does not narrow, so the reflex that normally protects you from bright light does not kick in. So the rule is: do not stare into the LEDs up close, close your eyes or wear protective goggles when treating your face, and stick to the session times. When that is and is not needed is explained in Should you close your eyes during red light therapy? That red light can actually help the eye in other circumstances is covered in Red light therapy eyes.
Sources
- Lydahl E. Infrared radiation and cataract I: epidemiologic investigation of iron- and steel-workers and II: epidemiologic investigation of glass workers. Acta Ophthalmologica 1984. The two studies behind the idea that “infrared causes cataracts”. Occupational exposure to molten metal and glass, not LED lighting.
- IEC 62471: the standard for photobiological safety of lamps. It classifies light sources by their risk to the eyes and skin, with separate limits for blue light damage, retinal heating and infrared.
