Heat Transfer Analysis of the Human Eye During Exposure to Sauna Therapy

Abstract

Among the reported health benefits of a sauna session are weight loss, detoxification of the body, and improved blood circulation. Side effects of sauna therapy, both beneficial and detrimental, also exist. It is well known that the human eye is one of the most sensitive parts of the entire human body when exposed to high ambient temperature and humidity levels such as in sauna therapy. This sauna heat interacts with the human eye and may lead to a variety of ocular effects due to radiation emitted by the heater and high ambient temperature. However, the resulting thermophysiologic response of the human eye to various exposure conditions during sauna therapy is not well understood. Therefore, it is of interest to investigate the potential ocular effects that may occur during sauna exposure. This study presents a numerical analysis of heat transfer in a heterogeneous model of a human eye exposed to sauna. The heat transfer model is developed based on porous media theories. In the heterogeneous human eye model, the effects of room air temperature and heater temperature on the intraocular temperature increase are systematically investigated. The study intends to focus attention on the different heat transfer characteristics between conventional sauna (mainly convection) and infrared sauna (mainly radiation). The results show that at the same room air temperature, the circulatory patterns within the anterior chamber of the eye in regard to infrared sauna are more rapid than those for the conventional sauna. Moreover, eye temperature is also higher in the infrared sauna than in the conventional sauna. The maximum temperatures of the eye exposed to conventional and infrared saunas at room air temperature of 80°C are 48.25°C and 52.90°C, respectively. From the values obtained, a guideline can be recommended to indicate the limitations in regard to temperature increase in the human eye due to sauna therapy.