Low Vision News

For low vision specialists and those who consult them

Sony Reader: a missed opportunity for low vision users

My PhD student and I had a play with a Sony Reader electronic book yesterday to see how useful it could be for low vision users. The answer: not very.

Although it has a text zoom feature, on their supplied ebooks the maximum text size is about 0.7logMAR. Given that you need an acuity reserve of at least 2x to read fluently, this means that you need 0.3logMAR (6/12; 20/40) or better to use it.

Maximum contrast is also poor: peak Michelson contrast is 60% which again means that the contrast reserve will be insufficient for most low vision users.

We did find one workaround to get larger print size (convert a document to PDF in large print, then put that into the Reader) but that’s inelegant.

This is a real missed opportunity for Sony: more zoom, reversed contrast and more control over text presentation would be simple to develop and would really expand the use of the Reader for hundreds of thousands of visually impaired people. Several of my patients have asked about electronic books and whether I would recommend them. Whilst I have yet to show any patients the system to see what they think, I’d be surprised if they end up liking it.

I’ve not yet seen an Amazon Kindle but am in the USA next week and will see if I can look at one. I know that, unlike the Sony system, the Kindle has text-to-speech so it’s at least made some effort to embrace users with poor vision.

Feel free to comment if you have any experience with any of these devices for people with poor vision.


6 responses to “Sony Reader: a missed opportunity for low vision users

  1. G F Mueden July 3, 2009 at 12:22 pm

    I would like to know more about the techniques of measuring size and contrast. The terms use were new to me. Please tell me where should I look.

    Here is my wish list:
    #1> A really good low vision/legibility message board Q&A for users and providers, creating a LV Special Interest Group, for detailed reports on ATs and how the users feel about them
    #2> A census of the population’s ability to read differev=nt combinations of type size and contrast. The present eye tests for acuity and contrast don’t give us the ability to set minimum stndards of legibility. Given a sample of printing below high contrast B/W, nobody can say what percent of the population an read it. If you are interested in the problem, please let me know.
    #3> I would like to find a realy good LV AT database with links to people who use the devices.
    This is a SIG idea.
    #4> I need an advocate, an expert to whom I can send examples of reader UNfriendly material, who would them Tell the publisher where he errs. My complaint is ignored. An expert in the field of print and screen legibility is needed.

    At 92 I don’t have much time left do push these things and I don’t want to reinvent the wheel. If these things exist, please let me know.

    BTW it would be nice if WordPress would install a larger font in thes text entry box so I could see my errors. ===gm===

    • lowvisionnews July 3, 2009 at 4:42 pm

      Many thanks for your very interesting response to my blog post. You raise some extremely interesting points.

      I am afraid I’m not able to answer all of your questions, but will certainly help out where I can…

      Text size is usually expressed in degrees of visual angle (that is, the angle of subtense of a letter (usually lower case letter x)). As a very rough guide, one degree of visual angle is about the size of your thumbnail viewed from arm’s length (so 1 degree would be about the size of text of a headline in a quality newspaper). In terms of measuring these, the easiest way is to relate them to an optometrists reading sight test (which is what I did).

      There are different ways of expressing contrast, but they involve using a photometer (light meter). The formula most commonly used is Michelson contrast, which is given by Lmax-Lmin/Lmax+Lmin, where Lmax is the brightness of the brightest item on the page (usually the background) and Lmin is the darkest item on the page – usually the print). Good quality print approaches 90% contrast, and reading performance drops off significantly as text gets fainter. Computer screens have much higher contrast.

      I agree that there should be a place where you can send examples of poor print quality. In my experience these items are often those which are important and relevant to older people, such as instruction leaflets in medicines. In England, the relevant agency would be the Royal National Institute for the Blind. I think the closest equivalent in the US would be the American Foundation for the Blind (AFB).

      Finally, your suggestion about a scale of what proportion of people would not be able to read text of a certain format is extremely good. To my knowledge this doesn’t exist.

      It would not be completely straightforward to relate to a proportion of people as there are several different variables (text size, text contrast, colour contrast) and some people may be able to read small but not faint print, or vice versa. Also, the environment for reading is important: as you will be aware, external lighting and the time you have been reading for are relevant factors (people can often read small print in a low vision clinic where the lighting is excellent and they are asked to read for 30 seconds, but would not be able to perform the same task at home with dimmer lighting when trying to read for 2 hours). But that doesn’t mean we shouldn’t try and perform a census along these lines. I will certainly discuss this with some of my research colleagues.

      I hope I have answered some of your questions. Many thanks again for your interest in this website.

      If I can be of any more help please do let me know.

      Best wishes

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