The Optic Nerve And Its Visual Link To The Brain

The optic nerve, a cable–like grouping of nerve fibers, connects and transmits visual information from the eye to the brain. The optic nerve is mainly composed of retinal ganglion cell (RGC) axons. In the human eye, the optic nerve receives light signals from about 125 million photoreceptor cells (known as rods and cones) via two intermediate neuron types, bipolar and amacrine cells. In the brain, the optic nerve transmits vision signals to the lateral geniculate nucleus (LGN), where visual information is relayed to the visual cortex of the brain that converts the image impulses into objects that we see.

In the retinal tissues of the eye, more than 23 types of RGCs vary significantly in terms of their morphology, connections, and responses to visual stimulation. Those visual transmitting RGCs are the neuronal cells. They all share the defining properties of:

possessing a cell body (soma) at the inner surface of the retina
having a long axon that extends into the brain via the optic chiasm and the optic tract
synapsing with the LGN. The RGCs form multiple functional pathways within the optic nerve to mediate the visual signal

Human beings can see three primary colors: red, green, and blue. This is due to our having three different kinds of color sensitive cone cells: red cones, green cones, and blue cones.

The RGCs connecting to the red and green cones are midget RGCs. They are mainly located at the center of the retina (known as fovea). A single midget RGC communicates with as few as five photoreceptors. They transmit red-green color signals to the parvocellular layer in the LGN (see Figure). The midget-parvocellular pathway responds to color changes, but has little or no response to contrast change. This pathway has center-surround receptive fields, and slow conduction velocities. Because of this pathway, we can see objects precisely in detail and in full color.

The bistratified RGCs are likely involved in blue color vision. Bistratified cells receive visual information input originally from an intermediate numbers of cones and rods. The bistratified RGCs connect to the koniocellular layers in the LGN (see Figure). The koniocellular neurons form robust layers throughout the visual hemifield and have moderate spatial resolution, moderate conduction velocities, and can respond to moderate-contrast stimuli. They have very large receptive fields that only possess on-center regions (no off-surround regions).

Objects can be seen in the dark with motion and coarse outlines accentuated due to the parasol RGCs. At the periphery of the retina, a single parasol RGC connects to many thousands of photoreceptors (many rods and few cones). The parasol RGCs project their axons to the magnocellular layers of the LGN (see Figure) and are primarily concerned with visual perception. They have fast conduction velocities, can respond to low-contrast stimuli, but are not very sensitive to changes in color.

Finally, humans can see objects in three-dimension courtesy of the crossing over of optic nerve fibers at the optic chiasm. This anatomic structure allows for the human visual cortex to receive the same hemispheric visual field from both eyes (see Figure), thus making it possible for the visual cortex to generate binocular and stereoscopic vision.

Recently, a new type of RGC, called photosensitive RGCs, was discovered. The photosensitive RGCs contribute minimally to our vision, but play a key role in vision regulation. Photosensitive RGCs axons do not have connections to the LGN, but form the retino-hypothalamic tract, and synapse to three other locations in the brain for specific vision regulation functions:

Pretectal nucleus: involved in reflexive eye movements, thereby helping to target what we want to see
Midbrain nuclei: involved in controlling the size of the pupil, thus helping to adjust the brightness of objects; and coordinating movement of the eye for focusing
Suprachiasmatic nucleus: involved in regulating the sleep-wake cycle

A fully functional optic nerve is essential for vision. Obviously, any damage of the optic nerve will sever the precise transmission of visual information between the retina and brain, directly leading to vision distortion and/or vision loss. Damage to the optic nerve can result from:

Direct/indirect physical damage (e.g. ocular trauma)
Acute/sub-acute physiological lesion (e.g. infection or inflammation, or malignancy (cancer))
Chronic neuronal degeneration (e.g. glaucoma, a most common cause of optic nerve damage)

Moreover, the optic nerve is also a very important vivo model for studying central nervous protection and regeneration. At the cell biology level, the RGC axons are covered with myelin produced by oligodendrocytes (rather than Schwann cells of the peripheral nervous system) after exiting the eye on their way to the LGN and thus part of the central nervous system. Scientists have recently acquired more and more evidence that certain types of damage to the optic nerve may be reversible in the future. Therefore, the optic nerve provides a potential window to explore more complicated neuronal degenerative diseases, such as Alzheimer’s disease and Huntington disease.

3/12/15

Jun Lin, MD, PhD
Assistant Professor,
Department of Ophthalmology
New York Eye and Ear Infirmary of Mount Sinai
Icahn School of Medicine at Mount Sinai

—–

James Tsai, MD, MBA
Chair, National Eye Health Education Program Glaucoma
Subcommittee President, New York Eye and Ear Infirmary of Mount Sinai Chair
Department of Ophthalmology
Icahn School of Medicine at Mount Sinai

February Is Low Vision Awareness Month

Help for People With Vision Loss

Here’s eye-opening news: Currently, 4.2 million Americans ages 40 and older are visually impaired. Of these, 3 million have low vision. By 2030, when the last baby boomers turn 65, the number of Americans who have visual impairments is projected to reach 7.2 million, with 5 million having low vision. For the millions of people who currently live or will live with low vision, the good news is there is help.

But first, what is low vision? Low vision is when even with regular glasses, contact lenses, medicine, or surgery, people have difficulty seeing, which makes everyday tasks difficult to do. Activities that used to be simple like reading the mail, shopping, cooking, and writing can become challenging.

Most people with low vision are age 65 or older. The leading causes of vision loss in older adults are age-related macular degeneration, diabetic retinopathy, cataract, and glaucoma. Among younger people, vision loss is most often caused by inherited eye conditions, infectious and autoimmune eye diseases, or trauma. For people with low vision, maximizing their remaining sight is key to helping them continue to live safe, productive, and rewarding lives. The first step is to seek help.

“I encourage anyone with low vision to seek guidance about vision rehabilitation from a low vision specialist,” advises Paul A. Sieving, MD, PhD, director of the National Eye Institute (NEI), one of the National Institutes of Health (NIH) and the federal government’s principal agency for vision research.

What is a low vision specialist? A low vision specialist is an ophthalmologist or optometrist who works with people who have low vision. A low vision specialist can develop a vision rehabilitation plan that identifies strategies and assistive devices appropriate for the person’s particular needs. “A vision rehabilitation plan helps people reach their true visual potential when nothing more can be done from a medical or surgical standpoint,” explains Mark Wilkinson, O.D., a low vision specialist at the University of Iowa Hospitals and Clinics and chair of the low vision subcommittee for the National Eye Health Education Program (NEHEP).

Vision rehabilitation can include the following:

Training to use magnifying and adaptive devices
Teaching new daily living skills to remain safe and live independently
Developing strategies to navigate around the home and in public
Providing resources and support

There are also many resources available to help people with low vision. NEI offers a 20-page, large-print booklet, titled What You Should Know About Low Vision, and companion DVD, featuring inspiring stories of people living with low vision. This booklet and DVD, among other resources, are available at
www.nei.nih.gov/lowvision.

With the aging of the population, eye diseases and vision loss have become major public health concerns in the United States. NEI is committed to finding new ways to improve the lives of people living with visual impairment. Aside from making information and resources readily available, NEI has dedicated more than $24 million to research projects on low vision, including learning how the brain adapts to vision loss; strategies to improve vision rehabilitation; and the development of new technologies that help people with low vision to read, shop, and find their way in unfamiliar places. Research like this will help people with low vision to make the most of their remaining vision and maintain their independence and quality of life.

2/17/15

The National Eye Health Education Program (NEHEP) of the National Eye Institute (NEI), a part of NIH, offers a 20-page, large-print booklet, titled What You Should Know About Low Vision, and a series of videos featuring patient stories about living with low vision. These and other resources are available at http://www.nei.nih.gov/lowvision.

Taking Control of Glaucoma

Taking control of glaucoma: The importance of adherence to glaucoma treatment

Glaucoma is known as the “silent thief of sight”: people with glaucoma usually have no symptoms. The only intervention that has been proven to reduce the risk of vision loss in glaucoma is lowering the eye pressure. The most common way to lower eye pressure is with eye drop medications. Glaucoma treatments do not improve vision, but they do to help prevent vision loss from happening.

What does it mean to be “compliant”?

Adherence (the newer term that is replacing “compliance”) with glaucoma treatment usually means taking your eye drops everyday and at the right times and coming to your glaucoma check ups. Your doctor needs to check your eye pressure regularly, as well as look at your optic nerves and measure your visual fields, to monitor your disease.

Why is it difficult to take eye drops everyday?

Some people with glaucoma only need 1 or 2 eye drops everyday to control their glaucoma, but some may need as many as 4 glaucoma medications, taken multiple times throughout the day. Imagine using 2 eye drops in the morning, 1 eye drop at noon, 1 at dinnertime, and 2 more in the evening, and doing this everyday for years and years, to help protect your sight. It is easy to see how people could miss some drops. Reasons can include forgetting them (or falling asleep before that bedtime drop), the cost of the medications, the side effects from the eye drops, and many others.

Why is adherence important for glaucoma patients?

In one word: blindness. The eye drops lower the eye pressure, which helps protect the eye from loosing vision from glaucoma. If a patient does not put in their eye drops, then the eye pressure will not be as low as it needs to be during that time and eye can be damaged. The damage from glaucoma is not reversible, so prevention is the goal.

What can you do?

If you have glaucoma and you take eye drops, use them everyday and as close to the right time as possible. Also, see your doctor for your glaucoma check-ups. Ask about your eye pressure readings, your optic nerve appearance, and your visual fields, so that you know what’s going on with your disease. If you are having any trouble getting your drops in (for example, increased cost due to change in insurance, always forgetting the morning drop, red eyes drawing attention at work), then tell your doctor about it, so you can make changes in your treatment plan.

Friends and family members can help, too. If someone you care about has glaucoma, think about asking them if they need any help with their drops. Some ways you might help: look at videos to see eye drop techniques, put in the drops for them, provide gentle reminders, or go with them to doctor’s visits to be a “second set of ears” on instructions and recommendations.

Taking eye drops for glaucoma is not easy, but it does work. Most people who are treated for glaucoma do not go blind. Take control of your disease, by taking your eye drops and going to your glaucoma check-ups.

For more information about glaucoma and treatment, visit www.nei.nih.gov/health/glaucoma.

1/29/15

Jullia A. Rosdahl, MD, PhD
National Eye Health Education Program Glaucoma Subcommittee
Duke Eye Center, Duke University

Glaucoma Awareness Month

In recognition of Glaucoma Awareness Month, here is a list of the top 20 things you should know in order to help save your vision as you get older.

What is Glaucoma?

1. Glaucoma is not just one eye disease, but includes a group of eye conditions that are a result of damage to the optic nerve thus causing vision loss. While unusually high pressure inside your eye (known as intraocular pressure – IOP) is often the cause, this may not always be the case.

2. It is one of the leading causes of vision loss in the US, and left untreated can result in blindness. It is estimated that 2.2 million people in the US have glaucoma, but only half of them have been diagnosed. While it primarily affects those over 60, it affects all ages with 1 in 10,000 babies born with glaucoma in the US.

3. The two most common types of glaucoma are primary open-angle glaucoma and closed angle glaucoma. Fluid in the eye flows through and area between the iris and the cornea and drains through the trabecular meshwork – this area is the “angle.”

Symptoms

4. Often call the “silent thief of sight,” open angle glaucoma, which affects 90% of those diagnosed, is not indicated by eye pain. There is a gradual loss of peripheral vison, generally in both eyes, and in the advanced stages there is tunnel vision.

5. The symptoms of closed angle glaucoma are easier to recognize and include eye pain, blurred vision, nausea and vomiting, vision issues in low light, halos around light sources and red eyes.

What to Expect From a Glaucoma Exam

6. Tonometry to measure your intraocular pressure. Your eyes will be numbed with eye drops making the procedure painless.

7. Dilated eye exam to look through your pupil to the back of your eye and the optic nerve.

8. Visual field test to check your peripheral vision.

9. Visual acuity to test your ability to see at a distance.

10. Pachymetry to determine the thickness of your cornea. Your eyes are numbed so this will be painless.

11. Gonioscopy to check the angle in the eye where the iris meets the cornea to help determine between open angle and closed angle glaucoma.

Treatment Options

12. Eyedrops are a common treatment options and may include more than one type. The importance here is to let your doctor know your complete medical history and comply completely with your doctor’s instructions to get the desired result. All include side effects and your medical history will allow your doctor to select the safest option. Some examples include:

Prostaglandins – they increase the outflow of the fluid in your eye and reduce internal pressure.
Beta Blockers – they reduce the production of fluid in the eye.
Carbonic anhydrase inhibitors – they reduce the production of fluid in the eye.
Cholinergic or miotic agents – they help increase the outflow of fluid from the eye.
Alpha-adrenergic agents – they reduce the production of fluid in the eye and increase the outflow of fluid.

13. Oral medications, such as carbonic anhydrase inhibitors, will be used if the eye drops cannot bring your eye pressure down on their own.

14. Surgery is an option if the medications or don’t work or you can’t tolerate them. In some cases you may need to continue using eyedrops. Surgeries include:

Trabeculoplasy – laser is used to unblock clogged drainage canals.
Viscocanalostomy – laser used to remove a small piece of the trabecular meshwork.
Aqueous shunt implant – small tube is inserted into the eye to improve drainage of the fluid.

Risk Factors

15. Age – you are 6 times more likely to get glaucoma if you are over 60.

16. Family history – you are 4-9 times more likely to get open angle glaucoma if someone else in your family has it.

17. Ethnicity – it plays a big factor in being diagnosed with glaucoma:

African Americans are at a higher risk than Caucasians of developing glaucoma; develop it earlier and experiencing permanent blindness.
Mexican-Americans have a greater incidence than Caucasians.
Asians are at increased risk for closed angle glaucoma, with people of Japanese descent being at higher risk for normal tension glaucoma.

18. Steroid use – long-term use increases the risk by as much 40%.

19. Medical conditions – such as diabetes, high blood pressure and hypothyroidism.

20. Other eye conditions – blunt injuries that “bruise” they eye (most commonly sports-related), retinal detachment and eye tumors, eye inflammation and certain eye surgeries are examples that increase the risk.

You can work to prevent, or at least lessen the effects of glaucoma on your vision by getting regular comprehensive eye exams, use any eye drops prescribed by your doctor to treat eye pressure according to their instructions, eat a healthy diets and wear eye protection to prevent eye injury.

1/20/15

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Spotlight Text – A New Way to Read

For People With Low Vision There Is Spotlight Text – A New Way To Read

Spotlight Text is a new e-reading app specifically designed to address the needs of patients with eye disorders. Dr. Howard J. Kaplan, a retina surgeon in the Hudson Valley, started developing the app five years ago. Dr. Kaplan states, “When the first Amazon Kindle came out, a light bulb went off. If books are now digital, you can make the text of the book adapt to the reader instead of forcing the reader to adapt to the text. My patients were extremely frustrated with low vision devices such as desktop readers. Most found them very difficult to use and affordable.” Working with low vision experts at the Lighthouse Guild International, various text presentation methods were evaluated. “The app is based on real visual science and was built with the input of the top low vision specialists in the country, “ says Dr. Kaplan.

The greatest difficulty in creating the app proved to be getting access to e-books. Initially Dr. Kaplan approached the major e-content providers such as Amazon, Google, and Barnes & Noble. All of them considered the low vision market too small to address. During the 5 years, Bookshare, a Silicon Valley nonprofit, began to expand exponentially. Bookshare is dedicated to creating an accessible library for the print disabled.

How Spotlight Text Works, and What Makes it Different
The app is seamlessly tied into the e-book library of Bookshare. The library currently has 300,000+ titles including all current and recent NY Times bestsellers. It has a very extensive collection of textbooks for K-12 children. E-book downloads are free and unlimited for children, and Vets. There is a minimal joining/maintenance fee for adults. All patients that have any visual deficit that prevents them reading standard print are eligible to join. A physician, optometrist, therapist, or even librarian has to certify a patient by checking a single box on the form and signing their name. Bookshare then does the rest by contacting the patient and giving them an account. Bookshare functions due to an exception in US copyright law that allows the free distribution of copyrighted material in formats that are unique for patients with visual disabilities. The books are coded in DAISY, which is a sound file format. The App takes these files and renders them back to written text.

The user interface is designed such that an 80-year-old technophobe or a five-year-old child can easily use it (Apple-like minimalism). The app also synchronizes with Bluetooth Braille readers that convert the text to Braille. It can be connected to the HDMI port of any TV for unlimited screen size (hardwire or wireless through Apple TV). As you will see when you demo the app, text is now dynamic: in both teleprompter and marquee modes the text will move so that ocular movements are minimized. Marquee mode was specifically designed and tested to work for end-stage Retinitis Pigmentosa patients and any patient with only a remaining very narrow central visual field. Using VoiceOver all books are now audible books.

Social Entrepreneurship
Special iTunes links are created for vision nonprofits. If a patient clicks on those links and purchases the Spotlight Text App, 50% of sales profits are donated to the organization, including the Discovery Eye Foundation or the American Academy of Ophthalmology Foundation. Prior to being placed on the AAO’s website the app was evaluated by its Low Vision Rehabilitation Committee. It is the only app that the American Academy of Ophthalmology has ever endorsed.

The Future
Dr. Kaplan hopes to return to the major providers of e-content and persuade them that low vision and blind users are a viable market for them.

“I believe universal accessibility is achievable, but it will take a coordinated and combined effort. Reading is such a vital part of all our lives, with e-books, everyone should be able to enjoy a good book.”

Howard J. Kaplan, MD
Retina Surgeon
Hudson Retina

1/15/15

Hadley’s Online Education for the Blind and Visually Impaired

12/4/14

The Hadley School for the Blind (www.hadley.edu) is the world’s largest educator of people who are blind or visually impaired as well as the world’s largest Braille educator. The school’s curriculum has always been delivered completely through online education, meaning students can study from anywhere at any time. Hadley serves nearly 10,000 students in all 50 states and approximately 100 countries. Hadley serves adult students, age 14 and over. Our mission is to promote independent living through lifelong, distance education programs for individuals who are blind or visually impaired, their families and blindness service providers.

Hadley courses are tuition-free for people who are blind or visually impaired and their family members; there is modest tuition for professionals. Students study at their own pace and receive personalized, one-on-one instruction from their instructor by phone, email, virtual “office hours” or mail.

Students can take courses in four formats: large print, Braille, audio or online. Since we began offering courses in an online format in 2002 as part of our eHadley initiative, more than 13,000 students have completed one or more online courses. 89 of our approximately 100 courses are offered in an online format, and 20 new online courses were introduced in 2014. Most of our online courses also are now accessible on mobile devices, so that students can literally study on the go if they choose.

If you’re not familiar with blindness, you may be asking yourself how a blind person can take courses online. The answer is through adaptive technology, such as screen magnifiers or screen readers. A screen reader is a software application that converts text on a screen to speech. One of the most popular is called JAWS. If a student doesn’t know how to use a screen reader, Hadley has a series of courses to teach them how to use this technology!

While many students come to us to learn to read and write Braille, we offer much more than just Braille education. In addition to Braille, some of our most popular areas of study include access technology, independent living skills, employment skills and recreation. These courses fall within Hadley’s Adult Continuing Education Program, which represents the largest number of students at Hadley. Some examples of ACE courses include:

Independent Living Series: This series of two-lesson courses focuses on a variety of topics central to the tasks of daily living. When individuals lose their sight, it can be overwhelming. They must relearn key daily living skills, such as cooking, dressing themselves and getting around. These courses give our students the tools they need to retain their independence and lead productive lives. The individual course topics include: orientation and mobility basics; clothing care and dressing confidently; socializing and dining; and cooking.

Self-Esteem and Adjusting with Blindness: Whether a student was born visually impaired or lost vision later in life, this course will help them understand the adjustment to life’s demands. Maintaining self-esteem with the changes and adaptations that come with blindness are discussed in-depth and illustrated with quotes from many blind persons.

Human Eye 1 and 2: These courses explain the parts of the human eye, how it works and how corrective lenses work. They enable the student to describe the basic anatomy, routine examination procedures and some common conditions of the human eye. Hadley also offers courses on some of the specific conditions that can lead to vision impairment, including: macular degeneration, diabetes and glaucoma. These courses are designed to help students living with these conditions to better understand them and how to manage them.

Developing Your Technology Toolkit: Technology plays a significant role in how people interact with each other, and most will likely encounter some aspect of technology in their everyday life. This course presents a variety of prominent desktop and mobile solutions. It also discusses how adaptive technology solutions provide access to mainstream hardware and software. In addition, it focuses on proprietary, adaptive technology products designed to be used specifically by persons who are visually impaired.

Enjoying Bird Songs: Listening to birdsongs helps people reduce stress, improve cognition and memory, interact with nature and even have spiritual experiences. This course guides students through the many bird songs presented in Hadley student John Neville’s audio CD set Beginner’s Guide to Bird Songs of North America. This course helps students become able to appreciate nature and birdsongs, as well as reflect on their experiences with birdsong.

Also part of the ACE program is the Forsythe Center for Employment and Entrepreneurship (FCE), designed to address the 70 – 80% un- and underemployment rate among people who are blind or visually impaired. The FCE is not an academic, college-level business program, but instead was designed to provide the requisite computer training; relevant social security, tax, accounting, legal, marketing, management and communications information; and content specific to the needs and concerns of visually impaired individuals who want to launch and grown their own businesses. All FCE courses are online, and many are just one-lesson modules, which makes learning quick and easy. Some examples of modules include: The Marketing Plan, The Business Plan, Forms of Ownership and Networking Skills.

Since the 1930s, The Hadley School for the Blind also has offered a nationally-recognized, accredited High School Program, available to students with visual impairments age 14 and up who live in the United States. Students may transfer credits from courses taken at Hadley to their high school to graduate locally. Students may also earn their high school diploma directly through Hadley. Frustration with local schools not offering quality vision services or accessible formats, difficulties passing the state-required exit exam for graduation or inability to travel long distances have prevented many of our students from earning their diploma in the past, so the Hadley High School Program is a much-needed “second chance.”

Courses are supplemented by Seminars@Hadley, free 60 to 90-minute webinars that are available to the public. These seminars are designed to bring together our blind and visually impaired students from around the world to discuss various topics in a virtual conference room with a panel, moderator and guest speakers. Participants listen to the seminar from their computer and post questions electronically. They also ask questions and/or make comments using a microphone. Seminar topics are timely, practical and determined by what our students tell us they need. Some of our most popular seminars include: Learning to Put the “You” in YouTube, Simplifying Internet Searching and Crafting with Vision Loss. Some seminars are approved for Continuing Education Credits (CEUs).

Hadley also offer a series of instructional videos on YouTube called iFocus (www.youtube.com/hadleyschool). These videos explain how to use the vision accessibility features on iDevices (Apple products such as the iPhone and iPad). Each video focuses on a specific task on iDevices, such as sending a text message or creating a calendar event . There are now 25 videos in the series, and they have been viewed nearly 10,000 times!

For more information about Hadley or to enroll, visit our website at www.hadley.edu, call our Student Services Department at 800-526-9909 or send an email to student_services@hadley.edu.

Kate Streit
Media and Marketing Specialist
The Hadley School for the Blind

E-Readers for Low Vision

11/18/14

While the devices mentioned in the November 13th post will help you read a hardcover or paperback book, what about an e-reader?

E-Readers for Low Vision

These lightweight portable devices come with a variety of options for people with limited vision, at a more moderate cost. The two we will look at are the Kindle and the Nook.

Kindle

There are two options here, an e-ink reader (the Paperwhite or the new Voyage), the closest to reading a paper page, or a full-color tablet. The only accessibility options for the e-ink readers are the ability to select a font you find easy to read and the ability to increase the font size. The increase in font size is a big help, but remember, that as you increase the size you will be “turning the page” more often – the screen size is 6” diagonally. The Voyage has a whiter background than the Paperwhite allowing for more contrast. Both include a built-in screen light that can be adjusted to your needs. One thing to note is that while it does have a screen light, it is not a backlit display as you will find in the Fire HDX. This might mean less eye strain.

The Fire HDX is a full-color tablet with quite a few more accessibility options and the screen sizes range from 6” to 8.9”. Since it is a full functioning tablet you can access email, play games, watch videos and a variety of other things. It has more large-font options (that can even be used for your emails), a screen magnifier that is easily activated with a triple tap on the screen and you can pinch to adjust the zoom and the backlit display provides high contrast. There are other options for people that are blind including a screen reader to describe actions taken on your screen, five accessibility shortcut gestures to help you navigate and even Braille support with a free app from the Amazon App Store. Because it is a backlit display you may experience eye strain if you don’t occasionally take reading breaks.

Kindle also has a free accessibility plugin that is downloadable for your Windows PC. It provides the following features: text-to-speech reading, voice-guided menu navigation, large font sizes, high contrast reading mode, keyboard navigation and accessible shortcuts. It is compatible with JAWS, NVDA and Microsoft Narrator.

Nook

Nook, like Kindle, has two options. An e-reader called the Nook GlowLight and a full-color tablet called the Samsung Galaxy Tab 4 Nook in 7’ and 10.1” sizes. As with the Kindle e-ink reader, the only accessibility options are the font and font size. There is also a built-in light to make the page brighter.

The new full-color tablets now made by Samsung, provide you with the access of a full functioning tablet such as email, playing games, watching videos, etc. The vision accessibility options include screen magnification for the text and pictures, TalkBack which reads aloud menus and on-screen options for navigating the device, negative colors to invert the color of the screen (text that usually appears black on white will be shown white on black), color adjustment if you are color-blind, and a text-to-speech option that will allow you adjust the rate at which text is spoken and your preferred text-to-speech program. Once again, these tablets have backlit screens that may tire your eyes after an extended period of reading, so take breaks.

E-Book Formats

The Kindle and Nook each have their own proprietary book formats, meaning that you can only read a book purchased for the Kindle on a Kindle or a Nook book on a Nook, however EPUB and CBZ formats can be easily transferred to the Nook. This is more important when it comes to borrowing e-books from a library. The EPUB format is more common when e-books are offered; and while some libraries now offer Kindle books, there are more EPUB titles. If you are comfortable with technology, you can use Calibre to convert most formats into whatever format you need.

Choosing between a Kindle and a Nook is based on personal preference. You can try out both devices before you buy them at Best Buy or Staples for the Kindle and at Barnes & Noble stores for the Nook. If you already own an iPad or Android tablet, remember you can also download the free Kindle and Nook apps from the App Store or Google Play.

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

For Book Lovers – Low Vision Magnifiers

11/13/14

The first of this month was Book Lover’s Day, and as an avid reader, I am willing to celebrate any day that is about reading. However, if you suffer from low vision due to age-related macular degeneration, cataracts, retinitis pigmentosa or other sight-threatening eye diseases, you may not be able enjoy reading as much as you used to.

There are several options to help you enjoy books again, including low vision magnifiers, e-books and tablets. We will provide you with a quick primer to help you select the best option for your lifestyle and budget. Today we will look at magnifiers and Tuesday we will explore e-readers and tablets.

Low Vision Magnifiers

There are several general classifications for magnifiers –

• Hand-held magnifiers – These are smaller and more portable, allowing you to read thins such as menus, price tags, prescription bottles and ingredients in addition to books. Some also come with built-in lighting that can help you see in low light situations. They can be as simple as a single glass lens to more advanced digital devices that can auto-focus, change text color and magnification or even let you snap a picture of what you are reading if steady hands are an issue. However, because of these are small enough to make them portable, the field of vision is small and reading books for any length of time might become tedious.

• Stand magnifiers – These are really better for reading books, magazines and newspapers as the field of vision is larger, your hands will not get tired holding the device and the distance between the page and the magnifier will remain more constant, making reading easier. This is especially important if you have tremors. However, these require sitting at a desk or table to be used.

• Magnifiers mounted on reading glasses – These are great for being “hands-free,” but they also limit your ability to see at varying distances, and are generally used for seeing things less than a foot from your nose.

• Video magnifiers – These devices use a video camera (similar to the portable digital device listed above) that focuses on the page and then magnifies it for viewing on a screen or monitor. Text color/background, brightness, contrast and levels of magnification can be adjusted as needed. As with the stand magnifiers, the ones able to scan an entire page of a book need to be used at a desk or table. However, now there are some machines that will even read out loud to you!

To get an idea of the range of devices available, along with the wide range of prices, here are three websites to get you started – Enhanced Vision, Optelec and Humanware.

Because each person has a different vision issue, not one magnifier works for everyone. A person with central vision loss from age-related macular degeneration will have different needs from a person with peripheral vision loss from glaucoma. That is why we suggest that you consult with a low vision specialist to help guide you in selecting the correct device for your specific needs.

Check back on Tuesday, or subscribe to the DEF blog, to learn about e-reader and tablet options for people with low vision.

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Diabetes Awareness Month & Diabetic Eye Disease

11/11/14

Even though people with diabetes are at a greater risk of developing blinding eye diseases, a recent study of Medicare beneficiaries show that very few of the people at risk have a preventative yearly eye exam.

Facts About Diabetes

In the US there are 29.1 million that have diabetes, 21 million have been diagnosed and 8.1 million are undiagnosed. Unfortunately, if left undiagnosed or untreated, diabetes can lead to serious health problems such as high blood pressure, increased LDL cholesterol, heart disease, stroke, kidney disease and blindness.

Although African-Americans and Hispanics are more likely to have diabetes, less than a third are aware of diabetic eye disease. And for those that have been diagnosed with diabetes, where a yearly eye exam is considered essential, ¾ of them have not had an eye exam in five years.

Diabetic Eye Disease – 3 Ways Diabetes Affects Vision

Diabetic retinopathy affects 28.5% of people 40 and older that have been diagnosed with diabetes. It happens when the blood vessels in the retina are damaged by leaking or blocking blood flow to the retina (the source of your central vision for reading, driving, recognizing faces, etc.) and if untreated, it can lead to complete blindness. In the very early stages there are no symptoms. And while there are some treatments that may help slow the progression of the macular edema, there is no way to regain sight that is lost.

Cataracts occur when there is a clouding of the eye’s lens, making your vision blurry or cloudy. While it is a normal for this to happen as a person ages, someone with diabetes is more likely to develop them at an earlier age. While beginning cataracts can be treated with glasses, when they become more advanced, cataract surgery will be needed to replace the cloudy lens with an artificial lens.

glauccoma diabetic eye disease — Courtesy of National Eye Institute, National Institutes of Health

A person with diabetes is nearly twice as likely to get glaucoma as other adults. Glaucoma is an eye disease that damages the optic nerve. The damage occurs when the pressure in the eye increases, squeezing the optic nerve and restricting its visual transmissions to the brain. Like diabetic retinopathy, you rarely notice any changes in your vision in the early stages, but as it progresses you begin to lose your peripheral vision. It can be treated with eye drops or surgery, but left untreated it can result in blindness.

Controlling Diabetes

Diabetes can be controlled, and some cases prevented, with careful attention to diet, watching your weight and exercise. Also learn your family medical history. You are at a higher risk of diabetes if a mother, father, brother or sister has the disease. If you are diagnosed with diabetes, make sure you have a yearly comprehensive eye exam to avoid vision loss. To learn more about diabetes go to www.ndep.nih.gov.

Susan DeRemer, CFRE
Vice Pesident of Development
Discovery Eye Foundation

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Facts About Diabetes

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