FACTORS OF VISION DISABILITY

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VISION

Vision disability can take many forms, including cloudy vision, tunnel vision, fragmented vision and total blindness. Making the environment as clear as possible by use of lighting, colour and tonal contrasts, boldness, clarity and texture will help a wide range of people. It will also make the environment safer for those who don't consider that they have any vision disability. Often, the consideration of vision disability issues can be pulled together as part of a design concept, rather than being seen as working against the designer's intentions.

CLARITY

The first step is to make any statement clear. Keeping the words simple, making routes obvious, highlighting elements that could become hazards can all help in a design concept. Lettering needs to be appropriately large and bold. Spidery thin lines may not be detectable at a distance.

Also placing items where they are likely to be seen makes sense. People with vision impairments can be concerned about where they are treading and will tend to look down rather than up. Signs at ceiling level may be missed.

CONTRAST

A good contrast helps everybody read text and signs. A white or yellow background is alright as long as the printing is thick enough to be seen against any glare if the item is read in a particularly strong light.

Printing over a picture background can cause confusion and detract from the clarity of the text. It is better to put the text to the side or on a plain background within the picture. Headings running across picture backgrounds may be alright if they are bold enough but care needs to be taken that the letter edges are clear whether they are against a light or a dark background.

Glossy finishes can spoil readability by creating reflections and glare.

TEXTURE

Texture can help in many situations. Tactile paving in the environment can act as a guide or a warning. However, it needs to be used sparingly and in correct situations or wrong messages may be given. The Mobility Unit of the Department of the Environment, Transport and the Regions (DETR) published guides on use of tactile paving on highway pavements.

Consultation plans on, say, park alterations can be made tactile by sticking on felt and sandpaper.

Dymo tape machines can add raised lettering to instructions or products.

The Royal National Institute of the Blind (RNIB) offer a tactile plan pressing service.

EDGES and BORDERS

Raised edges and tactile surface borders in the environment can give information and warnings to people with vision impairments. Raised edges can be detected by a long cane or a toe. Textured surfaces may be detected by the soles of the feet or by the tip of a rolling cane.

Logical routes should be carefully considered in designs and appropriate indicators provided so that a blind person can assess where they have got to and locate any obstacles in their way.

Busy routes need to be considered as being full of people who need to be given space to move out of the way of an approaching blind person. To achieve this, the blind person needs to be given indicators so that they can confidently walk through the centre of an area, leaving space to either side for other people to move into.

AUDIBLE

Audible information can help many visually impaired people. Voices in lifts advising which floor has been reached are an example. Sounds from different shops can be good indicators. Care is needed that unnecessary extraneous sounds don't obscure useful indicators.

Wayfinding technology is starting to provide 'smart' guidance around areas. Large developments should consider using this technology as it is helpful to everybody.

Having improved the accessibility of a facility or service, it is time to put the basic information onto an audio tape and send it to the local blind association or talking newspaper. Shout (or speak) about it so that it can be used and improve people's lives.