A recent study by Phillippa Cumberland and others revealed that just over half of adults aged 40-69 in the UK have refractive error of their eyesight, and nearly 20% of those adults had moderate or high degrees of short- or long-sight, sufficient to make spectacles essential.

Many of us have some degree of difficulty using computer displays, even the high-quality screens which normally come with Macs and iOS devices. Many of us could benefit from adjustments and tools to make access easier, whether as a result of visual or hearing problems, or because we find it hard to use normal methods to control our computers.

Tools to aid accessibility should thus be in great demand. But many of us are reluctant to use them, as we feel that we get on OK, and the tools are only intended for those with greater problems.

In this and future articles, I am going to look at what is available in OS X and iOS, and from third-parties, to enhance your use of Macs, iPads, and iPhones. I start with those built into OS X 10.11 El Capitan, in the Accessibility pane in System Preferences. If you haven’t opened it for a while (or ever), now is the time to do so: you could be surprised.

Many of the tools and effects controlled by Accessibility are performed in hardware, in the graphics card in particular, and do not show in screenshots. However, for the sake of the few comparisons I can make, below is a demonstration window from Pages with all Accessibility controls turned off, for comparison.

Vision

Display provides a suite of tools to change the appearance of the image on your display. Although many people with visual problems need the image to be magnified to some degree, sometimes more subtle changes can greatly enhance your ability to see and work with your display. Those provided include the following.

Invert colours does just that: black becomes white, white becomes black, and everything else changes too. This can be useful when working on mainly text documents, but is distracting if there are colour images around, because of its bizarre effects on them.

Increase contrast affects the many grey lines, boxes, and similar elements, but does not embolden text or make it any clearer.

Use grayscale puts the display into greyscale and drops all colour. You may wish to couple this with Increase contrast to make the grey graphic elements darker.

Reduce transparency eliminates transparency effects, which can be distracting in some situations in El Capitan. For most it is a subtle change.

Differentiate without colour does not appear to do much at all, although your experience may be different to mine.

Display contrast This slider control can only lighten or brighten the display from normal. Most people find it better to calibrate their display properly, and to ensure proper ambient lighting.

Cursor size enlarges the size of the cursor, as it appears at all times.

Shake mouse pointer to locate is a potentially useful tool for all. Wiggle the pointer, using your mouse or trackpad, and it gets larger, helping you locate it. I leave this turned on, in case the cursor decides to try to hide from me.

Zoom is a suite of tools to help those who need to enlarge the image on the display. If you are unable to correct your vision properly when using your computer (which is the preferred primary way to address this, of course), this can be invaluable.

Use keyboard shortcuts to zoom enables keyboard-controlled magnification. Defaults are Cmd-Opt-8 to toggle full zoom in or out, Cmd-Opt-= to zoom in, Cmd-Opt– (minus) to zoom out. Cmd-Opt-\ toggles smooth images, which makes little difference to my eyes.

Alternatively, you can use a scroll gesture with modifiers, the default being the Control key, to zoom. Under that default, if you have a Trackpad, simply hold the Ctrl key and swipe up with 2 fingers to zoom in, or down to zoom out. This is really rather neat.

Smooth images seems to make little difference now on high resolution displays, and Zoom follows the keyboard focus seems also to be subtle tuning.

With each, you can choose fullscreen zooming, or ‘picture-in-picture’ which uses a rectangular magnifying glass.

More options allows you to fix maximum and minimum zoom levels from 1 (normal) to 40, whether to show a preview rectangle when zoomed out, and the behaviour of zooming with respect to the movement of the screen image.

VoiceOver provides spoken (and Braille, if you have the hardware) descriptions of items on the screen, while you control the Mac using the keyboard. Normally this is toggled on and off using Cmd-F5, but must be enabled here first. Buttons allow you to train VoiceOver, and to open the VoiceOver Utility to adjust its settings, such as changing the voice used. This is very sophisticated, and I will explore it in detail in a future article.

One control which OS X does not currently offer, but which is of importance to those with vestibular disturbance, vertigo, and similar conditions, is to disable motion effects. The Mac journalist Craig Grannell, who suffers from this, is a prominent campaigner for Apple to add these controls, and I hope that he is successful in doing so. For the moment, there isn’t a great deal that you can do to minimise motion effects, other than to choose your software carefully.

Media

Descriptions enables the playing of audio descriptions for visual content in media, where they are available.

Captions enables subtitles and closed captioning when playing media supporting them.

Hearing

Audio has only two controls, which allow you to have the display flash when an alert sound occurs, and to play stereo audio as mono.

Interacting

Keyboard controls two features. The first enables Sticky Keys, so that you can use modifier keys without having to hold two or more keys at the same time, and is another feature which could help more people than currently use it. The other enables Slow Keys, which adjusts the time delay after a key is pressed and before it is activated. Anyone who finds keyboard use difficult should try using these controls, which could be very helpful.

Mouse & Trackpad enables Mouse Keys, which provides control of the mouse pointer using a keyboard number pad, and its settings.

Switch Control enables control using a wide range of other devices, such as foot switches, gamepad buttons, etc., and provides an editor to set those controls up.

Dictation enables voice control of computer and dictation of text, in conjunction with the separate Dictation & Speech pane. These are aimed at anyone who has difficulty controlling their Mac, or who finds it difficult to type text in using a keyboard. Although in the past dictation has been less than ideal, on modern Macs it can be as fast and accurate as using a keyboard, but does take a bit of getting used to.