Presentation software is commonly used in lectures and presentations of all kinds. There are a number of ways such presentations can be made more accessible to people with sight loss without compromising any of the essential content.
Small changes to the way in which the presentation is organised can go a long way towards improving the accessibility for blind and partially sighted people.
What are the factors to consider?
Before the presentation it is important to consider how the environment and basic room layout can affect accessibility through factors such as:
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Size and overall quality of the projected image
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Distance from the screen
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Stray light from windows and visual obstructions between the viewer and the screen
How can my presentation be optimised for people with sight loss?
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Enable people to determine their own optimum viewing distance from the screen. For example, you may need to reserve seats nearer the screen for partially sighted people.
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Try to avoid any stray reflections (e.g. sunlight from windows) or obstructions in the way of the screen.
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Ensure the image is as sharp as possible throughout the presentation by adjusting the focus if necessary.
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Adjust the keystone control properly on the video projector to achieve a rectangular display. Keystoning is caused by projecting onto a screen at an angle which typically results in the image appearing larger at the top of the screen and a loss of consistent focus. Many data projectors have a control to correct this.
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Try to avoid changes in the brightness of your slides by having a consistent background throughout the presentation.
Automated presentations
There are many situations where presentations are intended to run automatically perhaps as part of an exhibition or as a means of providing information for visitors.
In these circumstances it is also important to consider the speed at which the slides are changing if this is being done automatically. No hard and fast rules apply here because much depends on how much information is presented on the slide and how it is presented. A simple title in a large font will need less viewing time than a more complex chart or graph, for example. The important thing is to allow plenty of time for the information to be assimilated. Too slow is better than too fast!
In ideal circumstances you may want to consider having someone available with the automated presentation to offer any assistance as may be required and circulate copies of the presentation in other formats.
Further information on accessibility for presentation software can be found on the Slide design and layout, Multimedia in presentations, Transitions and effects, Producing handouts and Providing accessible formats pages.