Lighting has already been proven to help people with sight loss make the most of limited vision. Now a further challenge exists - discovering what specific lighting works best for different forms of sight loss. In Research Discussion Paper No. 5 Matching Lighting to Sight Lossseven key research questions are posed which would fill in missing data and help improve the quality of lives and independence of people with sight loss.
“Our studies have shown an urgent need to tackle unanswered questions,” said Anthony Slater, Lighting Development Manager. Missing data on how light affects specific vision is now a stumbling block for those wishing to use lighting to enhance the lives of people with sight loss.”
Since providing evidence that better lighting in general is vital to people with impaired vision, Thomas Pocklington Trust has funded two subsequent studies into whether lighting can be matched to different forms of sight loss.These studies, and a round table meeting of lighting and vision experts, exposed four fundamental problems:
- Missing data on which, and how many, people need different lighting as well as the specific needs created by their particular eye condition.
- Limited understanding of what people with sight loss find most important about lighting.
- Lack of understanding of lighting technology.
- Lack of knowledge on how to choose the most appropriate lighting.
Current guidelines on lighting, such as those from Society of Light and Lighting are mostly based on people with normal vision and may be inappropriate for people with sight loss. More light may be needed by people with some forms of sight loss, such as macular degeneration but may be detrimental to those with other forms, such as cataract. Both of these conditions are common in older people.
While the Code for Lighting acknowledges that it is essential to match the lighting conditions to the nature of a person’s visual condition, there is no detailed guidance on how to do this. Similarly, research into the effects of lighting on colour recognition has focussed on people with normal vision or specific forms of defective colour vision, but not on people with the more common forms of sight loss.
To address this lack of sight-specific knowledge, the new paper lists seven topics for urgent research.They include:
Key questions on how light works for people with sight loss:
- Its effect on safe movement: not just through brightness but also its role in balance and way-finding.
- Its influence on a healthy circadian system, the body’s natural regulator of sleep and wakefulness.
- The impact of different wavelengths of light on colour perception.
- The effect of indirect glare, both from lighting and from reflected light on walls and ceilings, on people with sight loss.
Other key areas of research include the specific tasks people with sight loss want and need to do, and which controls work best for them when switching lights on and off, and when dimming them.
The important role of optometrists is also raised, with a question of how to provide them with information about lighting so that they can pass it on to people having eye tests.
Said Slater: “As society ages and more older people experience sight loss, better lighting will be even more vital than today. We hope that researchers and those funding research will rise to this challenge as it is only by expanding our knowledge that technology can be developed to provide effective lighting for many forms of sight loss.”
