Lighting doing the heavy lifting
The bank holiday weekend here in the UK is always a bitter-sweet moment.
A chance to take the camper out for a last night under the stars, while the dew-drenched canvas and chilly dawn signal a shift into the season of mists and mellow fruitfulness.
It’s time to come indoors – and think about the lights.
I’m lucky enough to sit close to window to work. And I get to pedal down to the sea every day.
But millions of people living and working in the care sector don’t have that choice.
The vast majority of care homes I visit don’t make it easy for people to make the most of available daylight, with blinds pulled down to compensate for underpowered or undersized TV screens, chairs facing into the room, and staff offices and rest rooms squeezed into windowless corners below stairs.
So the artificial lighting has to do all the heavy lifting when it comes to delivering visual and ‘non-visual’ needs – especially critical for people who are vulnerable already – Circadian disruption and sleep disorders in neurodegeneration.
So it’s brilliant to see the SLL’s statement on integrative lighting by Dr Cosmin Ticleanu – Position Statement on Integrative Lighting.
Well worth a read, it’s a balanced summary of the ‘known knowns’ and the open questions that remain. It concludes with a practical message and a refreshing call for realism and honesty:
Provide brighter, well -timed daytime exposure; reduce melanopically stimulating light in the evening; protect darkness during sleep; and use daylight as the primary strategy wherever possible. Electric lighting can have an important role, but it must be specified using appropriate metrics and integrated with visual comfort, energy efficiency and user needs.
At the same time, the SLL cautions against over -precise or commercially convenient interpretations of the evidence. In particular, the daytime recommendation of a melanopic EDI of at least 250 lx at eye level should not be reduced to a short daily dose unless future evidence supports that interpretation.
Integrative lighting should be designed by competent professionals, applied with judgement, communicated honestly, and evaluated against both human and environmental outcomes.’
The LIA’s Ayca Dongahy and UCL’s Dr Jemima Unwin Teji are taking the debate to Westminster on the 7th of September, presenting to an All Party Parliamentary Group on Healthy Homes at Portcullis House in Westminster. They’ll be using WCS Care’s circadian lighting installations as an example of best practice. Great to see them getting the recognition they deserve. Register here – let me know if you can come and we can go in together!
A smile in the mind
Your brain is working hard behind the scenes to create a stable and useful picture of the outside world from poor and patchy data – a process called ‘top down’ interpretation of ‘bottom up’ stimuli. We only realise just how dominant those effort-saving top-down defaults are when we’re in an unfamiliar environment or the default is different or compromised in some way. That’s why it’s so refreshing – and tiring – to travel to a different country, try a new sport or food or start a new job.
Optical illusions are a great way of showing that principle in practice – like this version of the Beuchet Chair Illusion with Professor Claus Christian Carbon demonstrated by Professor Peter Thompson at the European Conference on Visual Perception last week.
When different objects – and people- are seen from a specific position, the brain adds them up to make a solid object – with unexpected results.
People living with degenerative conditions like Parkinson’s are at increased risk of visual hallucinations – where changes in the way the brain interprets edges, patterns and movement lead to confusing or frightening experiences. A recent paper suggested that over three-quarters of people living with PD experience hallucinations at some point in the course of the disease – Using illusions to understand hallucinations: differences in perceptual performances on illusory figures may underscore specific visuoperceptual impairments in Parkinson’s disease.
Another recent paper noted an increased risk of visual hallucinations for people living with dementia at the end of the afternoon, suggesting a link between low-light conditions and sundowning agitation – Light, sleep-wake rhythm, and behavioural and psychological symptoms of dementia in care home patients: Revisiting the sundowning syndrome.
What’s that got to do with the lights?
- Make sure light levels are as uniform as possible – the recommended difference between the brightest and darkest areas should not be more than 0.4. Changing from a standard dark-coloured lampshase to a wide, light-coloured one – with a diffusing panel wedged in the bottom is an efficient and affordable place to start.
- Manage confusing reflections from glossy and reflective surfaces like windows after dark. Draw sheer nets or curtains – choose low-contrast patterns to reduce risk of confusion when they’re open too. A simple magnetic clip or suction-hook for a curtain over a bathroom mirror is worth a look – Mirrored Self-Misidentification Syndrome: A Systematic Review of Cases.
- Put yourself in a loved one’s typical seating or standing position and notice any ambiguous shapes or movement in the edges of your field of view – shadows cast by car headlamps passing in the street for example. Patterns in the peripheral vision are more likely to generate a pleasant illusion or a distressing hallucination than those in the centre, as the brain ‘fills in’ the missing information – Illusion Reveals that the Brain Fills in Peripheral Vision.
That doesn’t mean designing out all the joy and personality in a space.
It simply means being intentional about the jokes you play.