Portable Artificial Vision Device May Be an Effective Aid for Patients with Low Vision
8 May 2016
In a small study that included 12 legally blind participants, use of a portable artificial vision device improved the patient’s ability to perform tasks simulating those of daily living, such as reading a message on an electronic device, a newspaper article or a menu, according to a study published online by JAMA Ophthalmology.
Low vision is a major disability and has obvious implications on patients’ occupational and social lives. When no treatment to improve vision is available, technological developments may aid these patients in their daily lives. One portable artificial vision device, OrCam, is an optical character recognition device, capable of recognizing text, monetary denominations, and faces, and can be programmed to recognize other objects. It includes a miniature camera and earpiece, which can be mounted to the right side of any spectacle frame. A cord connects the unit to a pack that houses the device’s battery and computer, which can be held in the user’s hand, clipped on a belt, or put in a pocket. The device can be activated by tapping it, pressing the trigger button, or by pointing at a target item. It takes a picture of whatever it is pointed at, which corresponds to where the user is facing. Using optical character recognition technology, the device then reads aloud any text found in the picture that was taken, which is heard only by the user via the earpiece and not by others nearby. The OrCam was recently made commercially available in the United States (current price, $2,500-$3,500).
Elad Moisseiev, M.D., and Mark J. Mannis, M.D., of the University of California Davis Eye Center, Sacramento, evaluated the usefulness of a portable artificial vision device (OrCam) for patients with low vision. The study included 12 legally blind patients, with best-corrected visual acuity of 20/200 or worse in their better eye. A 10-item test simulating activities of daily living was used to evaluate patients’ functionality in 3 scenarios: using their best-corrected visual acuity (BCVA) with no low-vision aids, using low-vision aids if available (such as magnifying lenses, electronic magnifiers, and smartphone applications for reading text), and using the portable artificial vision device. The device was tested at the patients’ first visit and after 1 week of use at home.
The researchers found that, after an initial training session, patients were able to perform the tasks better (at least 9 of the 10 items on the test) when using the portable artificial vision device. Average scores with the device were also better in 7 patients who used other low-vision aids. Unaided, no patient was able to read a message on an electronic device, a newspaper article, a menu, a letter, or a page from a book. The only item that most patients could perform by using only their BCVA without any other aid was recognizing monetary bill denominations.
Technical limitations of the device include that it cannot recognize special fonts and may be unable to recognize text if the contrast with its background is poor or under insufficient lighting conditions.
“This pilot study demonstrates that the portable artificial vision device may be an effective low-vision aid,” the authors write. “Further evaluations are warranted to determine the usefulness of this device among individuals with low vision.”
(JAMA Ophthalmol. Published online May 5, 2016.doi:10.1001/jamaophthalmol.2016.1000)