The computation of temperature rises in the human eye induced by infrared radiation.

Long-term industrial exposure to low levels of infrared radiation has for many years been associated with the development of cataracts; the injury mechanism is widely held to be thermal. A finite element model of the human eye is employed to calculate the temperature rises experienced by the intraocular media when exposed to infrared radiation. The model is used to calculate transient and steady-state temperature distributions for various exposure times and a range of incident irradiances. The effect of the eye's natural cooling mechanisms on the heating is investigated. Specific absorption rates in the infrared irradiated eye are presented. For a radiation source of 1500 degrees C, absorption of radiant energy by the iris and the lens combined with conduction of heat from the anterior regions is found to be responsible for increases in the lens temperature of 1-2 degrees C, but under extreme exposure conditions the temperature rises are found to be substantially higher.