For low vision specialists and those who consult them
Amazon Kindle…a better electronic book for low vision users?
July 29, 2009Posted by on
A few weeks ago I wrote about my experiences with the Sony Reader and whether it would be useful for a low vision user. The full post is here, but the punchline was: no, it’s not very useful for people with low vision.
However, I had high hopes for the Amazon Kindle 2. I managed to borrow a Kindle for a few days and performed some of the same tests with it as I did with the Sony Reader. Both devices use a similar size (15cm diagonal) electronic paper display, although the Amazon device is significantly thinner.
The most important function for a low vision user is text size. I had high hopes for the Kindle in this respect: its zoom function has six settings compared to three on the Sony. Unfortunately this does not mean larger text: the maximum text size is the same on both devices at 0.7 logMAR. This means that users without a visual acuity of about 0.3 logMAR (6/12; 20/40) would struggle to read the display for a prolonged period of time.
Interestingly, the minimum size is also the same (0.3 logMAR) so the Kindle just has more graduations of size between these two extremes. Maximum contrast is the same on both devices at about 60% Michelson contrast. This is probably a limitation of the electronic paper technology rather than anything else, so it’s perhaps unsurprising that this is the same.
One area where the Amazon device is far superior to the Sony Reader is in its experimental Text-to-Speech application. This is a relatively good text reader which speaks at about 200 words/minute at its maximum speed. 200 words/minute is slower than many experienced screen reader software users would select, but not far off “normal” book reading speed. Unfortunately the device does not include audio menus, although I understand this is being worked on.
There is some discussion amongst publishers as to whether text-to-speech violates Amazon’s copyright agreement (I imagine this is to do with audiobook rights, although there is a massive difference between automated reading software and a professional audio publication with a trained actor reading text).
So in summary, the Amazon Kindle is probably about as (in)accessible to the visually impaired user as the Sony Reader. If forced to choose between the two I would recommend the Kindle because of its text-to-speech function and I found its menu interface to be more intuitive.
Maybe the next generation of electronic books we accommodate those with low vision by allowing large print sizes?