FIGURE 2.

Proposed model of sundowning and the interaction between image forming and non‐image forming light, dementia and behavioural and psychological symptoms of dementia. Light entering the eye is illustrated as a triangle with the non‐image forming component (shaded blue/violet) and the image forming component (shaded beige). The tapering of the triangle indicates attenuation of light by different factors as labelled. The behavioural and perceptual consequences are shaded corresponding to their likely NIF and IF mechanisms