The FDA approved Second Sight’s “bionic” eye. While actually more of a retinal prosthesis, the implant is designed to assist patients with retinitis pigmentosa. The Argus II Retinal Prosthesis System has a resolution of 60 pixels. The device will not provide the HD type of vision that our eyes are capable of; however, more importantly, this technology will greatly aid a blind patient’s mobility and is a revolutionary step forward.
The system consists of a wireless retinal implant that rests on the retina. The patient will wear special glasses that see the image. The image will be sent to a visual processing unit that is worn on the patient’s hip. Once the data is processed it is sent back to the glasses which wirelessly transmit this data to the retinal implant. The implant electrically stimulates the photoreceptors simulating a coarse image. The patient learns how to interpret these light and dark images allowing them to navigate around and among obstacles.
The device was approved for use in Europe last year. Check out the video below from the European branch of the medical device company.
The US Bureau of Engraving and Printing has developed EyeNote™ a free, new iPhone app to aid the visually impaired or blind in identifying US paper currency. Essentially, the app is designed to allow the user to hold the bill in one hand and the iPhone in the other while scanning the paper currency. After a few seconds the iPhone will tell the user the denomination of the currency in English or Spanish. EyeNote™ can also operate in privacy mode with a different number of beeps signaling the value of the currency.
The app runs independent of a data connection. EyeNote™ can not differentiate between genuine and fake currency. EyeNote™ works on the following devices
4th Generation iPod Touch
Scan the QR code to the right with your iPhone to go to the iTunes EyeNote™ page.
Posted onFebruary 15, 2010|Comments Off on The Connection Between Light and Migraines
It seems that virtually everyone that has experienced a migraine wants to crawl into a dark room. The February 2010 issue of the journal Nature Neuroscience has published a study that explains why this phenomena may occur.
The study links a possible connection between light sensitive retinal nerve cells and nerve cells in the brain that are responsible for the perception of migraine pain. The study noted that blind patients also avoided light when suffering from a migraine, however blind patients that had lost their eye did not avoid light. The authors concluded that some of the retinal axons, included some light sensitive axons were sending signals to the hypothalamus, a part of the brain that is responsible for the perception of headache pain.
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Scientists at the University of Florida Restore Some Sight to Three Adult Patients with Congenital Vision Loss
One year ago the retina of two men and one woman in their 20s were injected with a harmless virus that contained vision correcting genes. All three patients lived with severe vision loss from a congenital problem call Leber’s Congenital Amaurosis Type 2. A gene responsible for a necessary protein used in the visual process is defective, gene therapy fixes the failed gene. One year after the gene therapy treatment these patients reporting being able to see light which was a significant improvement in their vision. One of the patients reported that she was able to see her parents clock, she had never been able to do this before. The study has two more years to run and it is likely that more patients will be added.
This is a very exciting medical development and shows that gene therapy holds great promise. There are so many genetic conditions, not only in the eye but the entire body, that can benefit from this type of treatment. Much research still needs to be done, however this lays the groundwork for promising future development. The exciting thing about this discovery is that it shows that it is possible to fix bad genes and improve people’s lives.
I started to write this post to inform patients with low vision about the added utility of using Firefox to make the screen more readable. Very simply you can magnify the Firefox window by holding down the CTRL key and then hitting the + key or the – key as appropriate to make the entire Firefox screen change size. The post then grew to including useful Firefox addons, which will be our next blog post. However, in researching other Firefox addons for low vision patients I came across LowBrowse™ and I am very glad I did. It is a great program for patients with limited vision from diseases such as macular degeneration, retinitis pigmentosa or glaucoma.
First of all the easiest way to get LowBrowse™ is directly from its developer, the Lighthouse International. The step by step instructions are very detailed and easy to understand. LowBrowse™ was developed in the Arlene R. Gordon Research Institute by vision scientist Aries Arditi, Ph.D. under a research grant from the National Eye Institute. Dr. Arditi has also developed larger mouse icons which are very essential to increasing a computer’s usability for patients with low vision as well as improving the functionality of LowBrowse™ for the severely visually impaired.
Installation was easy and no different than any other Firefox addon. Once the browser restarted a window appeared just above the Firefox tabs and below the toolbars. This window is where the magnified text appears and is referred to the reading window. Below the reading window is the normal Firefox browser window which is referred to as the global window.
The reading window is configurable as to the size of text, font and color. The default color of the reading window is white print on a black background. Initially the reading window was blank for me. I discovered that the Firefox extension “Tab Mix Plus” was interfering with LowBrowse™. Once I disabled the offending extension and restarted my browser my magnification window, or reading window as it is referred to in the help file, displayed text that was about 2 inches tall.
Once you place your cursor over any text in the global window, the text in that paragraph will be available in the reading window by scrolling through it with the left and right arrow keys. If the LowBrowse™ extension is enabled you can not use the left and right arrow keys for navigation in the large global screen, they are only available for scrolling text in the reading screen.
LowBrowse™ also has a text to speech function that was developed in cooperation with Charles L. Chen. I found the text to speech function to work very well and was quite accurate on my Windows Vista PC. The speech function worked very much like the magnification window. You place your cursor on the text you want to read in the global window and it reads the paragraph.
I found LowBrowse™ to be a great addition to our inventory of options available for patients with low vision. When combining Firefox’s inherent ability to magnify the webpage in the larger navigation window with the speech function and greater magnification capacity of LowBrowse™ it truly opens up the Internet to patients with low vision.
Two weeks ago I received an interviewed request from Sarah Robbins for the May 18 issue of Publisher Weekly regarding a blog article I wrote last month on how the Amazon Kindle could allow patients with Macular Degeneration to continue to enjoy reading books. You can read the entire article in Publishers Weekly here. I still like the Amazon Kindle for patients that need assistance in reading. Look for a review of the Kindle DX soon.
As with most doctors we are constantly on the lookout for items we feel may help our patients. The Amazon kindle has been out for a few years now, however they recently upgraded it. The Amazon Kindle, holds a lot of promise for patients that have poor vision as a result of macular degeneration, retinitis pigmentosa, glaucoma or any ocular condition that impairs vision.
What I like the most about the Kindle, for patients with low vision, is that it uses a high resolution screen with very high contrast letters, black print on a white background, just like a book, however, most importantly you can increase the size of the letters. Changing the font size is a great option for patients with impaired vision that want to read books. As you can see in the photo the Kindle is about the size of a paperback book, however it is as thin as a pencil, weighing in at just over 10 ounces, which is less than a paperback book.
Most new bestseller books are about $10, however many books are less than that. There are currently 250,000 titles in the Kindle library. It takes about 60 seconds to download a book wirelessly with the included wireless network (using Sprint’s Cellular Data Network), no WiFi necessary. The Kindle holds 1500 books, with your library backed up by Amazon, so if you have to make room for a book and years later want to reread it you just download it again at no charge.
I also like the kindle for patients that find it difficult to hold a heavy book or have a hard time turning the page such as those with MS or patients that have had a stroke. The Kindle also has a text to speech option so it can even read to you. Subscriptions to major newspapers are available as well.
Let me know what you think. I would appreciate hearing your thoughts.