The impact of light on older people and people living with dementia – Research by Newcastle University
At amBX, we enable our partners to excel by empowering them with data visualisation, connectivity, integration and sophisticated lighting algorithms. Circadacare is a new science-led start-up. They support older adults in care environments and people living with dementia through a fine-tuned full spectrum circadian system. They improve the wellbeing of older adults, ensuring healthy, natural human circadian rhythms for improved sleep and mood whilst supporting a reduction in falls.
For Circadacare, amBX is providing bespoke dashboard solutions and facilitating integration with other key building technology such as Nursecall systems. The user-friendly interfaces are designed to be used by Care Home Managers and staff. A significant benefit is that they require no technical training to be able to operate the system.
amBX software powers the Circadacare solution. Our carefully designed circadian lighting algorithms have been developed over many years to offer precise, granular control. They closely emulate natural light and support residents through the healthy benefits of circadian light.
Furthermore, Circadacare has conducted research in conjunction with Newcastle University to establish the impact of light on older people and people living with dementia. The report highlights many benefits that can be achieved, and this academic foundation provides credibility and support for the innovative start-up.
The research project gained academic insight from Professor Anya Hurlbert, who is a world expert in visual neuroscience with a research focus on human visual perception of colour. In addition, Naomi Gross is a PhD student supervised by Professor Hurlbert who studies the effects of light on wellbeing and behaviour and has provided insight into the literature.
Some of the key highlights from the research report are outlined below:
The “blue-light hazard” vs. “the blue light buzz”.
The report discovers that there is a trade-off between providing stimulation to the non-visual pathway to optimise circadian rhythms and guarding against damage to the eye.
Short-wavelength light at high doses damages the lens and the retina (the “blue light hazard”)
Yet short-wavelength light is also the most effective in activating melanopsin, the photopigment in the intrinsically photosensitive retinal ganglion cells (ipRGCs) that feed into the non-visual pathway that governs the sleep/wake cycle and other biological rhythms.
amBX Commentary: Therefore, blue lighting, in particular, needs to be managed with extreme precision. The amBX SmartCore lighting control software powers circadian lighting solutions. We support our partner, Circadacare, allowing them to deliver this solution to care environments. The carefully developed lighting algorithms support elderly occupants by reducing wavelength content below 455nm is advised while ensuring sufficient power around 460-480 for the circadian stimulus.
It is clear that the melanopic lux and photopic lux (brightness) of light needs to be personalised / tailored to each individual, depending on their eyes, their environment, and their personal biological rhythms.
Lighting, therefore, needs to be tuneable both in spectrum and in overall irradiance. It is important to remember the amount of melanopic lux depends not only on the light spectrum and overall irradiance but also on the individual’s eyes.
amBX Commentary: Given the various conditions residents within a care home may experience it is important that we can offer lighting that supports all of them. Whether that is cataracts, yellowing of the lens, restriction of pupil size, macular degeneration or something more extreme like dementia – it is clear the same light levels aren’t appropriate for all. Even increasing general light levels to support people with varying degrees of vision can have a huge impact e.g. reducing the number of falls.
The impact of light on elderly people
In older people, accumulated light toxicity contributes to cataract formation, which in turn reduces the amount of short-wavelength light that reaches the retina.
Cataracts, and the less extreme age-related yellowing of the lens, are therefore protected against further light-induced damage but they also reduce visibility as well as the effectiveness of short-wavelength light stimulation of the non-visual pathway.
Other age-related changes in the eye, such as restriction of pupil size, also reduce the overall amount of light that reaches the retina. The shorter the short-wavelength light, the more harmful.
Light requirements for elderly.
For older people, light during the day should be bright enough to ensure good vision, contain enough melanopic lux to ensure good sleep/wake cycles and sleep quality, but low enough in very short wavelength power to guard against further eye damage.
Dynamic vs. static light during the day.
There is still a question over whether changing melanopic lux of light over the day – from high levels in the morning to low levels in the afternoon – brings greater benefit than static melanopic lux during the day.
A recent study suggests that having regular daily exposure to light with a fixed amount of melanopic lux, for a sufficient duration each day, over a long period of time, is enough to ensure a good sleep/wake cycle and good sleep quality in older people (Figueiro et al., 2020).
The effectiveness of good lighting in preventing falls.
Poor vision and poor cognition both contribute to the likelihood of falls.
The visual and non-visual effects of improved lighting may therefore also reduce the incidence of falls.
Falls are more likely to occur at night when there is poor lighting.
Falls are also more likely to occur in people with disrupted circadian rhythms.
Appropriately designed light delivery may therefore be a powerful therapeutic agent in helping to regulate and strengthen circadian rhythms as well as enable better vision at night without disrupting sleep.
amBX Commentary: In our experience, we found that emergency lighting within bedrooms was often an issue, the constant small green light can disrupt sleep. Circadacare has developed an emergency light where the green LED indicator dims down to ambient light levels and goes off when dark. This is perfect for care home applications with circadian lighting that require the safety of emergency lighting but also the ability to have complete darkness and not disrupt natural circadian rhythms and sleep patterns.
The therapeutic use of light to affect our health and wellbeing (e.g. sleep, mood) is an ever-changing field that hasn’t found the optimal characteristics.
The field of research can be broadly thought of as before and after the discovery of the photopigment melanopsin, which has a peak spectral sensitivity around 480nm (Bailes and Lucas, 2013; Blume et al., 2019).
The culmination of this discovery and the technological advancement of LED technology which can fine-tune light spectra (Pattison et al., 2018) has led to some very recent positive clinical trials/intervention studies.