This research aimed to establish the optimal visual parameters, including illuminance, correlated color temperature (CCT) and color codes, of packaging for the elderly in a supermarket-type illuminated environment. Five illuminance levels (1100, 900, 700, 500 and 300 lux) were employed, where 700 lux was the average illuminance level found in five supermarkets in Bangkok, using light emitting
... [Show full abstract] diode (LED) light sources with a CCT of 6500 K, 5000 K and 3500 K. Packaging and labels were divided into the two groups of (i) colored packages with the product name and (ii) white packages with black text. Ten Munsell hues with a value/chroma of 5/6 and a TF Pimpakarn text-font of 17.5 points were selected for the first group. For the second group a black TF Pimpakarn font of 17.5 points on a white package was used. Thirty elderly (60–74 years old) and five young (21–22 years old) subjects, who had never changed their crystalline lens, were submitted to the following four procedural steps. (i) Their color discrimination was tested under a standard light booth and under a LED, both at 900 lux and a CCT of 6500 K. (ii) They were then given a random shopping list of 20 items and the explanation of color for each package was performed under the standard light booth (900 lux, 6500 K) before (iii) they were moved to the simulated supermarket, next to the standard light booth, and (iv) then attempted to select the 20 indicated items on their shopping list under one of the 15 different lighting conditions, repeating until all lighting conditions had been evaluated. The number of incorrectly picked (WP) items, total time spent (TTS) for picking and total error score (TES) of Munsell 100-hue test were recorded. No significant difference in the WP or TTS was noted with different illumination or CCT levels (or their interaction) in the elderly or the young subjects, but the two groups had significantly different WP and TTS levels between them under all lighting conditions with the elderly group taking just over two-fold longer to select their products.