Quality illumination and more to benefit the ageing eye
Current Australian standards do not take into account the decline in efficacy of the aged eye. Lighting designer and engineer, ALISTAIR DUNCAN shares the results of his research into whether low-energy lighting technologies can assist the ageing eye.
The old adage ‘seeing is believing’ takes a new twist as the ageing eye (over 50 years of age) begins to see less and less. For the older person, simple tasks such as reading labels or handiwork are more difficult and their anxiety levels rise without them understanding why.
The decline in visual performance is caused by a wide range of factors, resulting in the lack of ability to focus, clearly recognise objects or easily undertake simple tasks like reading books and labels or watching TV. All of these symptoms are normal for the ageing eye. Ageing eye diseases such as macular degeneration, glaucoma and cataracts further compound these problems.
An older person’s ability to navigate an interior space, particularly if new, can be more difficult, especially if lighting is highly uniform and of low contrast – even if it meets the minimum specified under ASNZ 1680 Lighting Standards (160 lux for public spaces). The aim for many facilities is to reduce energy lighting costs by installing lower wattage lamps, with the cheapest often being the major selection criterion.
In new builds architects and designers often respond to the low-energy challenge by increasing the impact of daylight, and using pastel colours for the décor and highly polished floors and work surfaces. This may be decoratively pleasing to the younger eye, but is confusing to the older eye. Too often the desire for brighter lighting causes even more problems due to discomfort and disability glare as light scatters within the older eye and causes visual blur, more so for those with eye diseases such as cataracts, which are particularly sensitive to bright lights.
Mobility is a key issue to ensure a person can navigate their way between areas. Lower lighting levels can reduce mobility of older adults, leaving them with a reluctance to move around from bedroom to dayroom, to activity room and back again. Lighting with poor contrast, low intensity and lack of discrimination between transition areas all affect an older person’s confidence in their movement and their sense of independence.
What size of lettering is used in your establishment? Is it well-illuminated and is it easy to discriminate between different signs? Even the size and typeface of signage is important. Easy to read signage that is illuminated well is another aid to mobility, and reduces anxiety levels as a person navigates interior and exterior spaces. Research indicates that symbols grouped in columns are easier to recognise. Also, letters or numbers grouped in sequences of five to six1, rather than the more popular three to four, will result in speedier comprehension2.
The implications go beyond the obvious navigation and reading tasks as they have an impact upon people’s physical health, sleep patterns, activity levels and eating enjoyment, and their general physiological well-being. This, in turn, impacts all – not just the elderly in aged or residential care.
European studies readily demonstrate the positive impact of quality lighting that is specifically tailored to assist older adults in their daily lives due to photobiological effects of lighting3. Put simply, lighting that is both of higher intensity and corresponds to the changing daylight colour profile, from cool white to warm white, results in a better outcome for older adults.
The adverse impacts on operational staff are not so obvious. Ineffectual lighting increases the level of care required as staff persuade people to move from bedroom to dayroom, to dining room, to activity areas and back again. Well-illuminated public areas reduce the risks of falls and injuries, preventing residents from ‘bumping’ into obstacles, or simply not seeing obstructions. Without this, the residents need more time and assistance from staff. The result is an increased workload and added stress for staff.
AGED CARE STRATEGIES
There are a number of strategies using lighting and colour that can be implemented to help alleviate difficulties in aged care lighting projects. Often, lighting is simply not bright enough for those over 50.
Research indicates that for every 10 years of age, lighting brightness needs to increase by up to 2.5 times4. Further research suggests 1000 lux is preferred5. Note the Australian Standard for common areas is only 160 lux. For the ageing eye, a six-fold increase is required. As outlined above, it is not just the physical and noticeable degradation of the eye, but the psychological effects that need to be considered to ensure a safe, enjoyable and anxiety-free environment for residents and staff.
Simply increasing light intensity with more lights of higher wattage is not the answer in today’s climate of increasing concern about energy costs. There are better approaches. The implementation of solid state lighting (SSL) can offer an effective solution, providing the issue of glare and colour temperature is addressed. Because SSL is often a point source of illumination and not diffuse, too much illumination can cause visual blur and visual adaptation problems. This is most apparent between transition areas as a person moves from one area to another.
Add poor lighting design and wrong colour illumination (as measured by Kelvin from warm white to daylight), inappropriate fittings, often with compact fluorescent lamps and badly positioned lights… the list goes on. A solution, now possible, is to install ‘tuneable’ SSL luminaires that automatically adjust their output to better reflect the daylight’s progression from morning to night.
Lights may not be the only problem; you need to also consider a plethora of aspects that are not so obvious. Other factors include too many uncovered windows and bright shiny surfaces, especially on floors and working surfaces. For instance, consider how décor impacts safety and well-being for the ageing eye. When selecting everyday items, how the ageing eye processes the visual image needs to be contemplated. It is not just about design and/or price. For the ageing eye there is a clear preference.
What benefits can we obtain if we design for the aging eye? First, if lighting is given care and attention, we can expect social benefits and happier, healthier clients, who are less prone to anxiety. Good lighting design that employs new low-energy technologies can help minimise these difficulties, lower energy usage and provide better illumination for all concerned.
Good lighting that is well-positioned and has the appropriate intensity, fitting, beam angle and colour temperature can result in the ageing eye and aged care managers worrying less, which in turn creates a safer living and working environment. Professional lighting designers can assist in assessing the risks associated with inappropriate lighting and the related glare issues.
There is financing available to help existing facilities to introduce lower energy lighting. The Government will assist with grants of up to around 40 percent if these technologies are implemented, as long as they meet the minimum standards laid down in ASNZ 1680. Naturally, there are more conditions, including an illumination audit, but these are not onerous.
The physical lighting and colour environment needs to be considered as a whole, and not just in part. The right choices for the ageing eye require decisions affecting all décor, surfaces, flooring, light fittings, the position of desks and tables near windows, lighting in bathrooms, position of mirrors, transition areas in corridors, how external pathways are lit, and how and where daylight is introduced to living spaces. These are subtle but important ways to care for clients and staff. The overall benefits may surprise you.
1. Darryl G. Humphrey (1999) ‘Age-Related Differences in Perceptual Organisation and Selective Attention: Implications for Display Segmentation and Recall Performance’, Experimental Ageing Research: An International Journal Devoted to the Scientific Study of the Ageing Process, 25:1, 1-26.
2. D Kahneman and A Henik (1977) ‘Effects of visual grouping on immediate recall and selective attention’, in S Dornic (Ed), Attention and Performance (pp 307±332). Hillsdale, NJ: Erlbaum.
3. A Charlotte, C Sust, P Dehoff, D Lang and D Lorenz, ‘Improved quality of life for resident dementia patients’, St Katharina research project in Vienna, Zumtobel Research, March 2012.
4. O M Blackwell and H R Blackwell, ‘Visual Performance Data for 156 Normal Observers of Various Ages’, Journal of the Illuminating Engineering Society, Vol 1, No 1, pp 3-13, October 1971.
5. S Sorensen and G Brunnstrom 1995, ‘Quality of light and quantity of life: An intervention study among older people’, International Journal of Lighting Research and Technology, The Chartered Institution of Building Services Engineers, London England, Vol 27, No 2, pp 113-119, 1995.
Alistair Duncan is a lighting designer and engineer. He is currently a PhD student at the University of Sydney and is conducting research on the effect low energy lighting has on the older adult and how this impacts their mobility in internal spaces. Alistair has an MSc in illumination from the University of Sydney and was awarded the Architectural Science prize in 2011 for Illumination. He also has an MBA and a certificate in Company Secretarial Practice.
In 2005, Duncan founded the Eco Living Centre, which specialises in providing advice and products within the sustainability marketplace. Prior to 2005, his previous experience was in senior management and marketing roles