Thermal cataract, from furnaces to lasers.
BACKGROUND
Thermal cataract has long been known as an occupational disease in furnace workers. This affliction has virtually disappeared in western countries due to improved working conditions. However, new light sources have appeared on the scene, in particular lasers, which might also be capable of producing thermal cataract. The aim of this survey is to review the history and describe the present state of knowledge.


METHODS
Experimental work, mainly on rabbits, was reviewed and complemented with the results of calculations on the thermal changes in the ocular media.


RESULTS
Safe exposure limits were derived over the optical spectrum from the near ultraviolet to the far infrared.


CONCLUSIONS
Lasers may be a cause of thermal cataract only in the near ultraviolet. Moreover, in this field of research too, it is concluded that science may be regarded as the present state of misunderstanding.
Vos
Johannes J
JJ
TNO Human Factors, Soesterberg, The Netherlands.
van Norren
Dirk
D
D000818:Animals; D002386:Cataract / Q000209:etiology*; D004781:Environmental Exposure; D006358:Hot Temperature / Q000009:adverse effects*; D007834:Lasers / Q000009:adverse effects*; D012449:Safety; D014466:Ultraviolet Rays / Q000009:adverse effects