Some folks selling far infrared saunas try to scare you away from near infrared (NIR) tungsten lamp saunas by telling them to google “glassblower cataracts”. The truth is that exposing tissue to NIR light has been shown to promote tissue repair and that NIR lamp saunas are quite safe for the eyes. These tungsten-lamp-sauna opponents want you to look at an article published in 1984 reviewing cataract formation in Swedish glassblowers. 1 This article used very old data showing that industrial glassblowers developed cataracts thought to be caused by infrared light exposure, mainly near infrared light. We now know that the article’s conclusions were seriously flawed and that cataract formation in the glassblowing industry is a complex phenomenon.2
A Ridiculous Comparison
Glassblowers in old unregulated factories with no modern safety standards were exposed to tremendous amounts of radiation. That exposure included infrared light but there was also ultraviolet exposure and even more ionizing radiation. The overall energy levels that the workers were exposed to were quite high. The workers also toiled in an extremely hot environment exposing their eyes to thermal injury. The total effect could be similar to staring at the sun! They were additionally exposed to a variety of toxic chemicals and particulate substances.
Telling people not to use near infrared saunas because they will get cataracts is like telling them not to use lights at night because looking at the sun will damage your eyes. It is an argument used by those that can not argue on the facts, since the facts do not support their argument. Tungsten lamp saunas emit very low levels of infrared energy compared to a glass factory.
Research has shown that glassblower cataract formation is complex involving many factors including thermal injury and eye heating.3 Animal studies have shown that exposure to near infrared light alone does not cause cataracts to form. In fact cataracts tended to occur in those workers that were likely going to develop cataracts later in life no matter what their occupation was. After age 60-70 there is no statistical increase in glassblowers over that of the general population,illustrating the strong hereditary- and age-related nature of cataracts.4
Near Infrared Light Heals
The truth is that near infrared light is being used to treat eye disorders. Research has shown that near infrared light helps heal laser related eye injury, chemical eye injuries and other eye diseases.5 Over 1/3 of the sun’s light is near infrared light and every cell in our bodies have photo-receptors called chromophores that are designed to absorb near infrared light. Interestingly, the cells in our bodies do not contain any chromophores that absorb far infrared light. Medical uses of near infrared therapy have grown tremendously in recent years. NIR light has been shown to have many beneficial and health-promoting effects for eye and brain conditions such as diabetic retinopathy, age-related macular degeneration, Leber’s hereditary optic neuropathy and Parkinson’s disease. 6
Too much of anything can be bad but NIR lamp saunas used properly should not hurt or damage your eyes and may even help them. The energy levels within a NIR sauna and the overall heating are simply not in a dangerous zone.
- Lydahl E, Philipson B. Infrared radiation and cataract II. Epidemiologic investigation of glass workers . Acta Ophthalmol (Copenh). 1984 Dec;62(6):976-92.
- Voke, J. Radiation effects on the eye . Optometry Today. 1999; 8:30-35.
- Goldmann, H. Kritische und experimentelle Untersuchungen über den sogenannten Ultrarotstar der Kaninchen und den Feuerstar [Text in German] . Arch. Ophthal. Dec 1930; 125: 313-402.
- Ham WT Jr, Mueller HA, Ruffolo JJ Jr, Clarke AM. Sensitivity of the retina to radiation damage as a function of wavelength . Photochem Photobiol. 1979 Apr;29(4):735-43.
- Rojas JC, Gonzalez-Lima F. Low-level light therapy of the eye and brain . Eye and Brain. 2011;3:49–67.
- Eells JT, Henry MM, Summerfelt P, Wong-Riley MTT, Buchmann EV, Kane M, Whelan NT, and Whelan HT. Therapeutic photobiomodulation for methanol-induced retinal toxicity . Proc Natl Acad Sci U S A. 2003 Mar 18; 100(6): 3439–3444. Published online 2003 Mar 7. doi: 10.1073/pnas.0534746100