So I decided to look this up again. From (broken link removed to https://ehs.lbl.gov/resource/documents/radiation-protection/non-ionizing-radiation/light-and-infrared-radiation/)
Near‐Infrared Exposure and Cataracts
The most common eye disease associated with near-infrared radiation is cataracts. Prolonged exposure to IR radiation causes a gradual but irreversible opacity of the lens. Other forms of damage to the eye from IR exposure include scotoma, which is a loss of vision due to the damage to the retina. Even low-level IR absorption can cause symptoms such as redness of the eye, swelling, or hemorrhaging.
Cataracts caused by near‐infrared radiation have been noted historically in glassblowers and furnace workers. Radiation between 800 and 1,200 nm is most likely responsible for temperature increases in the lens itself because of its spectral‐absorption characteristics. Visible wavelengths may also contribute to the problem, since the heat absorbed by the iris could result in heat transfer to the lens.
Acute Skin, Cornea, and Iris Injury
IR radiation below 3,000 nm will penetrate into different depths of the cornea to varying degrees, depending on the specific wavelength. The iris can absorb energy only at wavelengths below approximately 1,300 nm.
IR thermal injury may have significant biological effects on the human skin. The IR-A rays induce free radicals in the dermis and diminish the skin’s antioxidant capacity, the main cause of premature skin aging.
Both the skin and the cornea are opaque to wavelengths >1,400 nm. Exposure to IR radiation in this region causes injury through thermal mechanisms, with absorbed radiation being converted to heat.
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BTW, you know that being a physicist doesn't, in itself, make one an authority on the effects of various forms of energy on living organisms, right?
