CIE 238 PDF

CIE 238 – Infrared Cataract

There has long been a debate about the dose response curve, action spectrum andmechanism for the production of infrared cataracts. Some scientists believe that thedamage mechanism is purely thermal, others suggest that there is some evidence thatit could be photochemical. If the mechanism is photochemical, a strong wavelengthdependence in the near infrared spectral region will be present, and this will havegreat significance for lamp safety, IR-A medical devices, occupational exposure limitsand the design of industrial eye protection. With the advent of high-power infraredLEDs and diode lasers as well as wavelength-tuneable infrared lasers (e.g. TitaniumSapphire laser), it is now possible for the first time to conduct a definitive andconclusive laboratory study of the action spectrum for infrared cataract.Manufacturers of LEDs, lamps and lasers should be intensely interested in the resultsof such studies. If the aetiology (cause) is purely thermal, the ambient temperature aswell as the spectral content of the infrared irradiation becomes important and this isreviewed in this report. Currently the weight of evidence suggests that the aetiologicalmechanism is thermal.