The effect of age on white light perception.

The way that persons from different age groups experience “white light” is investigated. Human eye lens transmission changes spectrally with age and this may influence the way that humans from different ages experiences light. Such a difference may be important in industrial and medical environments. Two different age groups, one group younger than 40 years of age and another group older than 50 years of age were subjected to the same “white” definition task. A conventional single-booth setup was used where observers were able to adjust the intensity of four coloured LED’s. Results of the psychophysical test procedure were used to generate specifications of two light sources, as selected by the two age groups. The two age groups selected two very different light sources when tasked to achieve a “perception” of white. Results show that the older group prefers a source with a colour rendering index number of 89 and the younger group prefers a source with a colour rendering index number of 74. The sources selected by the two age groups specifies correlated colour temperature values of 5150 K for the older age group and 6592 K for the younger group