Video magnification systems are much like other pieces of Assistive Technology in that they can be very intimidating and confusing at first glance. If you are shopping for your very first digital magnification solution for any of the myriad of eye conditions out there, you can quickly get overwhelmed at both the terminology, features, and sheer number of choices that are out there. This blog post is intended to help someone who is unfamiliar with video magnifier technology learn about the various options and advantages of the technologies available on the market today.
There are many manufacturers of video magnifiers located all over the world, each offering multiple units with different features. Video magnifiers vary wildly in screen size and possible magnification levels. On the market today are units that offer magnification from just over 1 times and some go as high as 70 times magnification. There are different camera and display configurations including traditional desktop units, portable handheld units, head worn units and all kinds of variations on these themes. There are also a host of other contrast enhancement and speech output options available that can provide critical assistance to a person with low vision. Each of these options should be weighed against the users visual acuity, visual field, contrast sensitivity, how quickly they experience visual fatigue and long term prognosis for their condition.
Many people with progressive vision loss reach a point where they are no longer able to read or see the things they need to see with the aid of glasses or optical magnification aids. Optical magnifiers are cheap and functional solutions for many people experiencing the early stages of vision loss however, when higher magnification levels are needed, the size of the lens gets smaller and smaller. For example, a 3 times magnifier could be as large as 100mm in diameter, offering a large field of view whereas as 6x magnifier can only be as large as about 50mm in diameter offering half the field of view. As the magnification continues to increase the lens size becomes even smaller, the field of view becomes smaller and the range in which it will focus properly becomes shorter. Generally speaking when a person requires 6 times or more magnification they should start considering video magnification solutions simply to allow for greater efficiency.
There is no standard way in which people lose their vision. Some eye conditions are treatable and can be arrested before there is significant vision loss. Others are untreatable and can ultimately result in total blindness.
It is important to mention that there is a difference between legal blindness and total blindness. Many people are considered legally blind who still have some functional vision. Legal blindness is defined as someone who has a visual acuity of 20/200 or less in their better eye (with correction) and/or a visual field of 20 degrees or less. Having a visual accuity of 20/200 means that they would have to be within 20 feet of an object in order to see it where someone with normal vision would be able to see the same object at 200 feet away. A normal healthy eye is able to see approximately 95 degrees towards your year and approximately 60 degrees towards your nose as well as 60 degrees upward and 75 degrees downward, so a visual field of 20 degrees or less is a significant loss in someone's field of view. However even with a designation of legal blindness most people still have a significant amount of functional vision which can be utilized to read if the correct enlargement and/or enhancement is put in place.
Different eye conditions also cause the vision loss to occur in different parts of the eye. For example, one of the most common causes of vision loss, particularly in Caucasian populations is macular degeneration also known as age-related macular degeneration (AMD or ARMD). Typically, without treatment, the loss of vision from AMD begins in the centre of the visual field and over time begins to progress outward until someone is left with only peripheral vision. Conversely a condition like retinitis pigmentosa (RP) causes loss of the peripheral vision and progresses in towards the centre until someone is left with little or no visual field. It is always important to begin the search for an appropriate vision aid with a good understanding of the the cause of the vision loss and how it is likely to progress. It is also important to determine if there are any complicating factors such as loss of contrast sensitivity due to things like cataracts or light sensitivity which may influence what type of visual aid is most appropriate.
Goals are important and a visual aid should help the end-user achieve their goals. For some people their goal may be reading the newspaper, checking the stock market listings and reading their bank statements. For others they may want to be able to watch the kids in the back yard and do craft work such a knitting. The types of units used to meet these goals, when considered along with the eye condition, may be completely different. Always start with a clear idea of what the goal is before setting out to find a solution.
Another key factor is knowing where you are going to be using your visual aid. If you're buying a portable unit then presumably you can use it wherever you want. But desktop units can be bulky and difficult to move. If you are looking for something to use in the kitchen to read recipes then make sure you know how much space you have available before you set out on your hunt for the best aid. Some people might have a limited office space and want something that can integrate with their computer. Others might want a large dedicated screen completely independent of any other device. Still others may be living in a seniors facility with very little shelf space and could want something that connects to the TV in their room. Different units can meet different space requirements and usage scenarios. So knowing where you want to work is an important consideration up-front.
If someone likes to travel then they likely will want something they can take with them on the road. There are many types of portable units. Handheld units are one type but there are also lightweight units and folding units which are quite easy to transport. Some offer HDMI output which would allow someone to plug them into most hotel room TVs. Others have portable screens. The ideal portable unit for the end-user will depend upon where they are going, what they have available to them at their destination and how much weight they are willing to carry with them.
Optical Character Recognition (OCR) is the process of taking printed text and converting it to computerized text which can then be read to the end-user with a speech synthesizer. Many people with vision loss find it difficult or impossible to read for extended periods even with text enlargement and enhancement. They may be able to read for short bursts, to check the mail or their bills for example, but to read anything longer can be a struggle. Optical Character Recognition allows them to sit back and listen to the text being read to them rather than having to try and struggle through on their own. This is an extremely powerful feature offered on many units these days, including some portable units.
Head worn systems utilize a camera and virtual reality glasses to present an image directly in front of the eye. These systems have their advantages and their disadvantages. For people who have narrowed visual fields, such as the example of retinitis pigmentosa earlier, these units can provide magnification, text enhancement but most importantly they can take a narrow field of vision and expand upon it. Unfortunately for many people with central vision loss, as in the example of macular degeneration earlier, the visual output from these units often falls directly in the area where the patients vision loss is most profound which can render them effectively useless. It is very difficult to say with certainty when one of these types of devices will work for any given patient and there really is no substitute for trying them to see how effective they are. However it's important to note that with progressive central vision loss these are unlikely to be the best solution.
Overkill is a thing! Putting an advanced, multi-touch screen, computer compatible system with OCR in front of a 90 year old grandma may not be the ideal starting point. Knowing how technically savvy someone is at the outset can help find the best recommendations. The simplest units on the market have only three controls: Power, color mode and size. These are the three most important features overall and often times the only features someone needs to read. The more features there are the more buttons that will be needed. The more buttons there are the more likely it is to create confusion. The more confusion there is the less likely the end-user is going to feel comfortable using the machine. In the end the most important consideration is what will help someone achieve their goals with the least apprehension. Always start with a clear recognition of the end-users technical abilities and comfort with technology. Some grandma's are rocking the iPad, email, programming their TV independently and spent a great deal of their professional careers with computers. Others did not and wouldn't be comfortable with an excessive number of controls.
Some units can connect to computers. They do so in a variety of ways. There are portable units which create their own WiFi hotspots and allow iPads and Android tablets to be used as their displays. This can be powerful particularly if someone has an eccentric viewing angle (not using their central vision). It is easy to move a tablet to exactly where their vision is strongest. Others can connect via USB connection and allow a computer screen to be shared with part of the computer showing, for example, a Word document while another part of the screen shows an enlarged document from the camera. Still others connect through an HDMI or DVI connection directly to a montior and can be put through a simple push button A/B switch to change back and forth between the computer image and the video magnifier image. There are also all-in-one units which are both a video magnifier and a computer all built into one unit. Again much of the consideration for which type of unit is most appropriate will come back to the amount of space available. The most efficient setup is generally to have one screen for the computer and a second screen for the magnifier, but space limitations don't always make that practical. There are also certain task specific jobs such as data entry where it may be advantageous to have all the information on one screen.
Working height is another factor which will be determined from your goals. Some people want nothing more than to read paper and materials that are generally flat. For these people working height really isn't a factor. However if you are wanting to build a scale model of the Death Star, you need a camera that will accommodate you and allow you to position the camera so that you can properly paint that ridiculously vulnerable exhaust port - assuming of course we're talking about the original Death Star. Everyone knows that was fixed in the second generation Death Star. Some cameras are mounted on swing arms and allow a huge amount of movement. You could swing the arm over an architectural drawing, for example, without having to move the drawing. Some are on shorter arms but allow enough working space for arts and craft work and include the ability to lock the focus at a certain height so that you're not fighting with autofocus while trying to keep your crochet in sight.
Screen size is often determined by the effects of the eye condition. People with macular degeneration tend to function more efficiently with larger screens as it helps them make use of their remaining peripheral vision. Someone with retinitis pigmentosa on the other hand might not gain any advantage from increased screen size as the extra height and width falls outside of their narrowed visual field. Often people make this decision based on budget but the primary decider should be what is going to work best over the long term when factoring in the likely progression of their visual loss.
Many units have X/Y tables underneath them so that materials can be easily and smoothly panned around beneath the camera. Other units do not come with this option and other still have optional external tables that can be put in place when they are wanted. If you are using your unit for any kind of long-term reading such as newspapers or books, this can be a very important feature. These tables do take up desktop space however and some people prefer to keep the desktop space flat and uncluttered so that it can be used for any purpose. Again this is a factor that space limitations will likely influence as much as the desired use of the video magnifier.
Over the years, with the adoption of digital cameras and monitors, video magnifiers have become more and more reliable. They are by no means invulnerable though and problems can occur. The length of warranty should be considered as it is a measure of how confident the manufacturer is in the quality of their product and likely the devices longevity.
If you live in Vancouver and the nearest repair centre for your device is in Montreal it's going to be expensive to ship and it's going to be gone for a while while a repair is conducted. Always ask where you can get your unit repaired if something comes up. Also ask how you will be supported by the seller. Some vendors of these devices will leave any repair warranty or non-warranty entirely between you and the manufacturer. Other vendors will provide pickup support, cover shipping costs and may provide loaner units while yours is away. Two vendors selling exactly the same unit at the same price may have very different repair policies. For example, at Canadian Assistive Technology we will cover shipping costs to the nearest repair centre while the device is within it's warranty period, and will provide loaner units for the time it is away. Whenever possible you should hang on to the shipping materials your vision aid came in, just in case there's an issue. The packaging and inserts are specifically made for each unit and it is dangerous to ship the units in anything other than their factory packaging for most larger units. We also partner with our repair partner at Chaos Technical Services who repair many of the brands we represent. CTS has an excellent track record and their turn-around time on repairs is unmatched by anyone in Canada.
What happens if you pick a unit and it turns out to be less than ideal? We believe that every end-user of a large print visual aid should have 30 days to determine if it's right for them. If it's not a good solution then return it to us, no questions asked. You will get a full refund - minus shipping and any missing parts that need to be replaced or repaired. There is no point in being stuck with a vision aid that provides marginal function and having it do nothing but collect dust. We want to ensure that you find the solution that will work best for you. Be very careful to ask about any vendor's return policy as many of them will put a restocking fee on for anything that's returned and with devices like these that can be quite expensive. Where ever possible minimize the risk if you are not 100% sure that a given device will work for you.
At Canadian Assistive Technology we have many years of experience in helping people select the right visual aid. (In case the Star Wars reference didn't give away our age) We can help you, starting with a simple phone conversation (shameless plug -- call us today at 844-795-8324!) to help narrow down the field to units that would provide the best match of form and function. We can then follow it up with a home visit to try the selected unit(s) to determine if they are indeed the right device to meet the need. At the end of the day we are confident we can provide the best solution with the best support available.