Researchers have made low-resolution devices useful in a new way. Instead of trying to replace the blind‘s vision entirely, the devices now “translate” text, presenting it to the user in a more familiar format… Braille.
According to NBC News, today’s retinal implants are promising and allow those who suffer from certain kinds of visual disabilities to see very rough shapes and contrasts. But with a resolution of only a few hundred total pixels, they are only able to see the world in the lowest fidelity.
People with no visual disabilities take the ability to read things like street signs and menus for granted. Not only is this difficult or impossible for most visually-impaired people, there are relatively few accommodations available.
With this dillema in mind, the team at Second Sight decided to modify an Argus II retinal implant system, in which visual signals are presented to the retina in the form of electrical signals.
They hooked the built-in camera up to software program that translates text it sees into Braille. After translating the image into Braille, it is then sent to be displayed by the implanted electrode arrays.
Low resolution isn’t a problem for Braille, since letters are represented as dots in a three-by-two grid rather than using the lines and curves of standard glyphography.
In testing, they would show up to four letters at a time. This is not efficient for reading longer sentences, but it is enough to quickly differentiate between “left” and “right,” “open” and “closed,” or “men” and “women.”
Their test subject had limited success with the system. The subject was already a user of Braille and the Argus II implant, so he was able to identify letters correctly 89% of the time. But as the length of the word grew, success rate fell.
Still, any improvement over the previous system would surely be welcome to users of the implant. While for reading books and articles, Braille is much faster.
Retinal implants are still something of a rarity; while hundreds of thousands could potentially benefit from the technology, they are still in a relatively early stage of development. But whenever they start to be distributed and prescribed to the general population, having helpful alternative modes like this one could be very important.
The paper describing the research, “Reading visual braille with a retinal prosthesis,” appeared recently in Frontiers in Neuroprosthetics.