Designing for visual impairment on World Sight Day
Today is World Sight Day, an annual day to focus global attention on those living with blindness and visual impairment.
When it comes to designing beautifully accessible spaces, it is important to design for those with varying degrees of sight loss or visual impairment. Visual impairment can be used to describe a wide range of disorders including blurred vision and obstruction of visual fields. Some people have only peripheral vision and some have only central vision. Around 5% of the population is colourblind which can affect how they see colour schemes. Others can have difficulty differentiating between colour and different tonal values or adjusting to abrupt changes from dark to light environments.
There are 2 million people in the UK with sight loss that is severe enough to impact their ability to drive and 10% of people aged 65 and over have some form of sight loss.
On World Sight Day, we’ve put together a selection of design considerations to create beautiful and functional environments for those with visual impairments.
This is one of the most important design considerations when creating an inclusive space for someone with a visual impairment. It’s important to ensure that the colours and materials used make the room easy to navigate and read. This can be done by measuring the Light Reflectance Value (LRV) of materials meaning the darker the colour, the lower the LRV.
British Standards guidelines recommend that there is a 30 point difference between the LRV of walls from that of the ceiling and the floor in order to help anyone with a visual impairment accurately gauge the size of a room. It is also equally important to make sure that door frames, handles, locks and other openings are highlighted using the LRV scale.
Fixtures and fittings
The approach to colour contrast can be applied to key furniture and fixtures too. If support rails are required they should be finished in a contrasting colour or material to the wall behind them, as should items like basins and toilets. Curtains and blinds can have a trim highlighted in a contrasting colour to help users find the edge.
Where furniture is placed into a design scheme the material used for the seats should contrast tonally by 30 points of LRV to the floor below it, as should the material used to finish tables and floors. This helps a person with visual impairment make out where the edge of furniture is and avoid falls and injury. Contrasting piping around the edge of furniture can further aid someone with a visual impairment to make out the shape and location of seating.
It’s important that flooring materials have consistent tonality throughout. A bold change in colour could be perceived by someone with a visual impairment as a step or change in level which can cause trips or falls. Similarly, patterns can cause confusion and make a space seem smaller and more chaotic.
If you want to use different flooring materials but to also ensure it’s suitable for those with a visual impairment, it is recommended that the floor finishes are within 5 points of LRV. This means the floor will appear as one flat, even surface.
Shiny or reflective floor finishes can appear wet to those with a visual impairment, creating a need for extra caution and can lead to confusion. Similarly, shiny surfaces should be avoided for wall finished too as they can distort the perception of a room’s size and shape.
Lighting plays a big part in any design and in particular spaces for those with visual impairment. Poor lighting will result in pools of light and dark on the floor, and no matter how well considered the material finish or colour contrast, a person with a visual impairment will struggle to navigate the space. Consistent, even lighting should be applied throughout and in particular across the floor.
Lighting can be used to raise attention to important design features, such as walkways ad signs but should be used carefully so as not to create shadows that could cause confusion.
Natural daylight is the best form of lighting for any environment, but elements such as glare and moving shadow can be hard to control. Indirect natural daylight, for example through a high-set window, minimises the chances of glare, confusion caused by views or shadow, and distraction associated with other sensory and cognitive impairments.
Signs are a key element of any public space and can help with decision making and finding important locations – such as toilets and emergency exits.
Where signage is used there are many design considerations that can make it easier for a visually impaired person to navigate:
- Text should be written in sentence case format as someone who cannot interpret individual letters can make out the shape of the word easier than if the word is written in full capitals
- Fonts should be sans-serif (without extending features at the end of the stroke) as these are easier for those who are visually impaired to read due to the simplified nature of the typography
- Where possible, icons should be used to accompany text. Icons should be of the end-use of the location described rather than a conceptual symbol eg. a bathroom could have a symbol of a toilet, rather than the universal symbol of a man and woman or ‘M’ or ‘F’
- British Standard guidelines recommend that white text on a dark background is easier to read than black text on white but 70 LRV points of difference should be achieved between text/symbols and the background material of all signage
Physical aspects of an environment will also have an impact on how a visually impaired person can navigate the space. For example, having level access on train platforms, in bars and restaurants, shopping malls and exhibition spaces will make these spaces considerably easier for those with a visual impairment to use and decrease the potential trip hazards.
Similarly support rails, perching benches and quiet seating spaces are extremely useful for people with limited vision who may feel a little uneasy on their feet.
As with any well-designed inclusive environment, making spaces better for one group positively impacts the space for another. Many of the design considerations recommended for those with visual impairments will also hugely benefit others with physical or cognitive impairments.
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