Posts Tagged Vision Impairment
Many people who have a stroke also experience vision impairment as a result. New groundbreaking research looks at the mechanisms that play a role in this damage and shows that it may be reversible.
A stroke can affect different parts of the brain. When it occurs in the primary visual cortex, which is the region of the brain that processes visual information, the lack of oxygenated blood can mean that the neurons (brain cells) active in that region incur damage.
In turn, this will affect people’s ability to see, and they may experience various degrees of vision loss. While some people who experience vision loss after a stroke may spontaneously regain their sight, most individuals do not.
So far, specialists have believed that damage to the primary visual cortex neurons causes a set of cells in the eye’s retina called “retinal ganglion cells” to become atrophied, meaning that they lose their ability to function.
When retinal ganglion cells become atrophied, it is highly unlikely that a person will ever recover sight in the affected area.
However, a new study, the findings of which appear in the journal Proceedings of the Royal Society B, has uncovered more information about the brain damage mechanisms relating to impaired eyesight.
“The integration of a number of cortical regions of the brain is necessary in order for visual information to be translated into a coherent visual representation of the world,” explains study co-author Dr. Bogachan Sahin, Ph.D., who is an assistant professor at the University of Rochester Medical Center in New York.
“And while the stroke may have disrupted the transmission of information from the visual center of the brain to higher order areas,” he adds, “these findings suggest that when the primary visual processing center of the brain remains intact and active, clinical approaches that harness the brain’s plasticity could lead to vision recovery.”
Therapies should ‘encourage neuroplasticity’
In the new study, the researchers worked with 15 participants who were receiving care at Strong Memorial and Rochester General Hospital for vision damage resulting from a stroke.
The participants agreed to take tests assessing their eyesight. They also had MRI scans to monitor their brain activity and an additional test that looked at the state of the retinal ganglion cells.
First, the investigators found that the health and survival of the retinal ganglion cells were highly dependent on activity in the associated primary visual area. Thus, the retinal cells connected to inactive brain areas would atrophy.
At the same time, however, the team surprisingly noted that some retinal cells in the eyes of people who had experienced vision impairment were still healthy and functional, even though the person had lost sight in that part of the eye.
This finding, the researchers explain, indicates that those healthy eye cells remained connected to fully active brain cells in the visual cortex. However, the neurons failed to correctly interpret the visual information that they received from the corresponding retinal ganglion cells, so the stimuli did not “translate” into sight.
“These findings suggest a treatment protocol that involves a visual field test and an eye exam to identify discordance between the visual deficit and retinal ganglion cell degeneration,” notes the study’s first author Dr. Colleen Schneider.
“This could identify areas of vision with intact connections between the eyes and the brain, and this information could be used to target visual retraining therapies to regions of the blind field of vision that are most likely to recover,” Dr. Schneider adds.
In the future, the researchers hope that their current discovery will allow specialists to fine-tune current therapeutic approaches or develop better strategies that will stimulate the damaged brain-eye connections to “rewire” correctly.
“This study breaks new ground by describing the cascade of processes that occur after a stroke in the visual center of the brain and how this ultimately leads to changes in the retina,” says senior author Brad Mahon, Ph.D.
“By more precisely understanding which connections between the eye and brain remain intact after a stroke, we can begin to explore therapies that encourage neuroplasticity with the ultimate goal of restoring more vision in more patients.”
Brad Mahon, Ph.D.
But recently, he figuratively cut the cord to his desktop and joined the mobile revolution. Morales was visiting an area Veterans Affairs blind rehabilitation center, learning how to use an iPhone’s features for people with vision impairment.
“It’s pretty amazing,” Morales said, demonstrating how he can call up a song and play it with a few taps. “Whatever I can do on the computer I can basically do it on the iPhone. It has the same capability.”
The smartphone, a gadget designed for the sighted, has turned out to be a godsend for those who are blind and visually impaired, making them more independent than ever before.
With VoiceOver, the iPhone’s built-in gesture-based app that reads text on a touch-screen aloud, or Google Android’s TalkBack, users who are blind can access anything on their phones. The user activates apps with a few gestures — single finger to explore and find buttons, one-finger touch to identify things on the screen and double-tap to push the button after it’s located.
“It’s a learning curve, but you can learn to do every single thing on an iPhone that anyone else can do,” said Lee Huffman, editor of AccessWorld, published by the American Foundation for the Blind. “These devices are opening up a whole new world.”
It didn’t look like it would turn out that way at first.
“The blind community started getting really panicky” when smartphones and later, tablets, took off following the iPhone’s debut in 2007, researcher Joshua Miele, associate director of Smith-Kettlewell Eye Research Institute in San Francisco, recalled. “Touch-screens were a real concern.
”But in 2009, Apple included VoiceOver in its mobile operating system, and followed up with the personal assistant Siri in 2011, launching a new world of mobility for the visually impaired. Google added TalkBack, a screen reader, to its Android operating system in 2009 and Google Now, a personal assistant, in 2012. Microsoft mobile has similar features.
“It’s made a huge difference, productivity-wise,” said Jennison Asuncion, accessibility leader at LinkedIn, who is blind. “I use my mobile phone probably even more than lot of people.”
Erin Lauridsen, 32, a trainer at the Independent Living Resource Center in San Francisco, has been blind since birth and grew up using expensive, clunky, single-purpose devices for doing coursework in school. “When the iPhone 3GS came out with VoiceOver built in it was a huge game-changer for me and a lot of other people,” she said.
She uses an app called BlindSquare for navigation; Money Reader to identify currency denominations; and Voice Dream Reader to assemble audio play lists of documents from many sources. She also uses Uber and a lot of other popular apps.
“I’m on an equal footing with what everyone else does — the Yelping, Facebooking and Twittering,” she said.
People who are visually impaired want to use their mobile phones like anyone else, said Astrid Weber, who researches user experience at Google, visiting people who are visually impaired in their homes to see what they need and how they use technology.
“Mobility is really important for them,” she said.
Google Now — the Android personal assistant — is popular with users with vision impairment, said Eve Andersson, manager of Google’s accessibility engineering. Her parents who are vision impaired use it all the time, she said. “They ask their phones questions, ask it to call me, ask it for directions and create reminders. They love being able to do that with their voice.
”For years there have been screen readers for desktop computers. OutSpoken, developed by Berkeley Systems in the late 1980s, was the first for the Mac, according to Smith-Kettlewell’s Miele, who worked for the company.
But while VoiceOver and TalkBack broke the tether to the desktop, third-party apps still have to be made accessible to people with disabilities.
There’s a legal issue too. The Americans with Disabilities Act requires websites and mobile applications to be accessible, said disability rights lawyer Lainey Feingold, although regulations are still being worked on by the U.S. Department of Justice.
Google announced Google Impact Challenge: Disabilities last year with a $20 million grant for technology innovators in the nonprofit community who work on technology to make people with disabilities more independent. “We’re actively looking for proposals,” said Brigitte Hoyer Gosselink of Google.org….
Our friend Michael from Home Healthcare Adaptations has done it again! This time, he has created an infographic that explains what sensory impairment is, tells us the difference between vision and hearing impairment, and lists some really great apps for both types of impairment and explains how they work. Look at the infographic below for more details (click twice to enlarge). The apps listed are either free or very nominally priced.
Best Mobile Apps for Sensory Impairment
What is sensory impairment?
Sensory impairment or disability, is when one of your senses; sight, hearing, smell, touch or taste, is no longer functioning normally.
A person does not have full loss of a sense to be sensory impaired.
95% of the information about the world around us comes from our vision and our hearing.
Vision Impairment vs. Hearing Impairment
285 million people are estimated to be visually impaired worldwide.
39 million people are completely blind.
More than 4 in 5 people living with blindness are aged 50+.
360 million people have moderate to profound hearing loss.
Current production of hearing aids meets less than 10% of global need.
Approximately 1 in 3 people aged 65+ are affected by disabling hearing loss.
Mobile Apps for Vision Impairment
App: Tap Tap See
What it does: Uses the device’s camera and VoiceOver functions to photograph objects and identify them out loud for the user.
Features: Double tapping the screen enables the user to photograph any 2D or 3D object at any angle and define the object within seconds.
The device’s VoiceOver function audibly identifies the object to the user.
Includes the ability to repeat the last image’s identification and save the image to the camera roll with the attached tag.
Allows the upload of identified images from the camera roll and can share identification via twitter, facebook, text or email.
Platforms: iOS and Android
Cost: New users are provided with 100 trial pictures to start. 4 subscription plans are available starting from $4.99+.
App: Be My Eyes
What it does: It connects blind people with volunteer helpers globally via live video chat.
A blind person requests assistance via the app.
The volunteer receives a notification for help and a live video connection is established.
Utilises the iPhone VoiceOver technology which enables synthetic speech and a touch based interface.
At the end of each session there is a ‘rate it’ or ‘report misuse’ option both for the helper and the user.
Platforms: iOS. Android version in production.
Cost: Free, but a subscription may be put in place from September 2015.