Optical Low Vision Aids


Spectacles or eyeglasses form the cornerstone of optical low vision prescriptions. Any lens type or power that can be found in any of the other devices, can be mounted in an eyeglass frame.
These glasses range from stronger than usual reading glasses and bifocals (for patients with relatively good vision), to extremely strong lenses or lens systems that require very close working distances.
The principle patient objection to strong prescriptions is that a close working distance is required. This is often more of a psychological barrier than a physical one, although there is some initial arm discomfort when working at distances closer than about four inches.
Research has shown that a well adapted patient will read faster with spectacles than with any other optical magnification device. In fact, the only devices that can yield faster reading speeds are video and computer based devices costing at least ten to twenty times as much.

Hand Magnifiers
Hand magnifiers are the most familiar of Low Vision Optical devices. They are available in powers ranging from 1X to 20X. These are NOT the lenses you will find in your local hobby shop or dime store. The stronger powers should be made in aspheric curves to reduce distortion. The biggest patient complaint about hand magnifiers is that they become smaller as they become stronger. This is a limitation based upon optics. While in some cases it may be possible to create a larger lens if price is no object, there are physical limitations to the maximum size possible.

Limitations of Magnifiers:
The most common patient disappointment is when the size of the higher powered magnifiers shrinks.
I wish I had a dollar for every time someone said that the 5X magnifier I just prescribed would be perfect if only it covered the area of an entire page!
Unfortunately, the simple laws of optical design preclude the manufacture of very wide field magnifiers in high powers, at least at any reasonable cost.
One manufacturer once told me that they could produce what the patients want, but no-one could afford to buy it.
Indeed, manufacturers HAVE made improvements in the sizes of available magnifiers over the years, and I almost daily find myself explaining to patients why a particular magnifier costs $50 to $100 dollars when the ones their cousin Myrtle purchased in the 5&10 was only $4.00!
Quality optics are expensive (although most are still under $200.00). The higher cost magnifiers we prescribe are made up of computer designed ASPHERIC curves to minimize distortion. The process of design and manufacture of these high quality lenses requires an investment of tens of thousands of dollars to design every new lens. Compounding this is the fact that most of the devices we prescribe are made in Europe, inflating the price even more. The advantage however, is that patients have a better selection of magnifiers available today , than ever before.

Stand Magnifiers
Stand magnifiers are the easiest to use, of Low Vision Optical devices. They are available in powers ranging from 1X to 20X. These are NOT lenses you will find in your local hobby shop or dime store.
The magnifiers we use are manufactured with distortion reducing aspheric curves. They are available with and without built in illumination systems, both battery and plug in types. The most expensive models have electric halogen illumination with a built in Rheostat, or Dimmer.
While these devices are often the easiest to use, they are also the most optically complicated in use and in prescribing. Because the height the lens is mounted varies widely, relative to the lens’ focal length, some of these may produce unclear images when used with distance or reading prescriptions that do not match the design of the lens. Proper prescribing or Stand magnifiers requires not only knowledge of each particular lens’s idiosyncrasies, but a thorough knowledge of the patients prescription glasses as well.
Just as with Hand Magnifiers, the most common patient disappointment is when the size of the higher powered magnifiers shrinks.

Why not buy a magnifier from a store?
Several reasons:
1) Most stores that carry magnifiers have a very small selection of hobby or office based magnifiers in only low powers. These are not generally suitable for all but the best seeing low vision patients.
2) Magnifiers are frequently mislabeled in their power – OTC magnifiers labelling should be the subject of an FTC investigation, as powers are often given to magnifiers that have no basis in reality.
3) Third, patients have unrealistic expectations of how a magnifier should work. For this reason they often choose a “large” magnifier because it covers more area, only to find it doesn’t magnify sufficiently for their eyes.
4) Conversely, some patients become “magnification junkies” , selecting a lens that gives a high amount of magnification, but has a far smaller field of view than a lens of appropriate power for that patient’s eyes.

The proper lens power will allow for faster, longer, and more comfortable reading.
Whether the patient realizes it or not, the Doctor is constantly evaluating all of these factors and how they ultimately affect reading fluency and comprehension.

Sometimes magnifiers are provided with the experience based assumption that fluency may
improve with practice over several weeks. Most patients do see improvement , but some
patients will not improve. The more experience your specialist has in this area, the better.

Second, magnifiers, particularly stand magnifiers, must be chosen with the patient’s eyeglass correction in mind. Some magnifiers are designed to be used with distance glasses, some with standard bifocals, and some with entirely different lens powers.
Without a full understanding of the optics involved, it is easy to select a magnifier that will provide a blurry image, or one that will create eye strain, fatigue and headaches.

Most “low vision stores” are run by well meaning individuals who are frequently visually impaired themselves. Unfortunately, they most often do not understand the complex optics involved.
In short, the consumer has no way of knowing if a magnifier purchase in a store the power they really need. They may save some money in the short run, but delay getting the appropriate device, and pay much more, in the long run.

Electronic Magnification

CCTV’s
CCTV’s are Flat screen monitors coupled with a camera and some special circuitry to produce real time magnification of printed materials. Unlike a system you could create yourself with a camcorder, the circuitry helps assure higher contrast and reversed contrast of printed material.
A critical and often overlooked component of these systems is an x-y table. Some units are even sold without these in an attempt to reduce size and weight.
X-Y Tables allow for smooth movement of the pages or books under the CCTV’s Camera.
The smooth scrolling of printed material plays an important part in how many patients deal with their scotomas (blind spots) that are a result of their condition.

Portable CCTV’s
The latest and most progressive solutions in electronic magnification are seen in these devices.
They are offered in truly portable models with 3.5 to 5 inch screens and “luggable” models with 7 to 13 inch screens. Cost varies with screen size, features , and quality from around $200 to $2500 dollars. The scrolling effect from large screen CCTV’s with X-Y tables is not generally appreciated with these hand held devices.

iPhones and iPads (and other tablets and phones)
The Apple products get top billing here because Apple has taken steps to make their products more accessible. Print on iPhones and particularly in iPads can be significantly enlarged, and contrast enhanced, and APPS are available that convert printed materials into speech.
The problem is that your children , grandchildren, and friends, even if they are users of this wonderful technology, do not have the slightest idea of how to make the accessibility work.
A low vision provider can determine if this technology may help you, and give you information about using the accessibility functions and APPs, but ultimately you may need training of about 6 hours to learn to use these devices efficiently. A Low Vision specialist will generally know where you can get this training in your area.

E-Sight, NuVision and Jordy
The Low Vision field has advanced markedly in the last six years. Originally the LVES or Low Vision Enhancement system , was developed by NASA scientists and researchers fro John’s Hopkins Medical Center. This unit, a wonderful concept, was somewhat over-engineered and weighed over TWO pounds on the patient’s head.
Subsequently, another company, VES (Vision Enhancement Systems) introduced a unit called the V-Max. At 23 ounces it had some major advantages over LVES, but also had some serious shortcomings.

ENHANCED VISION then introduced the Jordy, which at under 10 ounces, delivered on some of the early promises of video technology. It cost a very reasonable $2800 but production ceased when the Olympus headsets it was built upon were discontinued.

For the last 2 years, the only player in the field was the E-Sight, which worked very well, but cost a staggering $15,000.
In the last few months new competition in the form of the “Nu-Vision” was introduced, at about $6000 with some shortcomings and some promised new features that may be exciting if they work well.

The Jordy 3 is due out in early 2017. If priced anywhere neat the original Jordy, it could be a real winner in this category. Stay tuned!

Hand Held CCTV Cameras
There are several of these low cost devices availble. Image quality is generally somewhat inferior to normal CCTV’s but they can provide an acceptable option when cost is the primary issue.
Cost is around $200-$350

Computers and Technology
At our services, we also have Assistive Technology available to demonstrate and evaluate patients for computer adaptations and modifications, and other state-of-the-art high-tech devices such as computer screen enlargement software, print to speech systems such as the Kurzweil and Eye Pal Solo, and portable video systems such as the Portable CCTV’s and Laptop Cameras along with iPads and iPhones.
Computers can enable visually impaired and blind individuals to work as efficiently as fully sighted workers. Many screen adaptation systems exist that allow the screen to either be enlarged for a low vision patient or to have the contents of the screen read in a computer synthesized voice. Some systems combine both technologies to further enhance performance.

There are so many choices, that it can be confusing. Vendors for these systems will tout their own systems, and in fact most are pretty good. Your Low Vision specialist can give you some unbiased guidance in this area, and then you should follow up by trying several systems from several vendors to see which fits best for you.

The Key is to KNOW YOUR NEEDS!
Employment or business needs require a computer.
Recreational Desires and personal needs may be met with a Table or Phone.
Minimal needs, particularly when you have little background computing experience, may best be service with one of the new speech only devices such as the Amazon Echo or Google Home.

Other considerations:
Other measures available include sunwear evaluations, lighting and environmental design consultations to maximize function in the patient’s real world setting, and visual therapy to enhance performance.

Lighting
Proper lighting is often crucial to optimize visual performance in patients with low vision. Most of the time, at the end of the low vision exam, we will recommend task lighting to enhance a patients ability to read printed materials. This is particularly important when the materials in question are of poor contrast, such as newsprint. We evaluate the amount of light that works best for each patient as the exam proceeds, and may further recommend a particular type of lamp. Mostly, we recommend reflector lamps, which concentrate the light onto the patient’s work area. We may also recommend a particular type of bulb, with either regular soft white bulbs, or neodymium bulbs being the most often recommended.
Most of the patients we see have more than one problem. For example, many of the patients with Age Related Macular Degeneration also have cataracts of varying degree. A strong level of illumination is usually required for the retinal problem, but the cataract causes glare from this higher illumination. The doctor must then consider further adaptations to allow for maximum illumination on the task while minimizing glare.

Absorptive Lenses
Many Low vision patients also suffer from glare outdoors in the sun. In severe cases, even indoor lighting may prove a problem for some patients. During the low vision exam, these problems are explored both by patient history and by observations and testing. When necessary, a trial of different absorptive lenses is done to find the best lens to reduce glare without compromising vision. While this is to some extent a trial and error process, the expertise of the doctor and his staff will assist the patient in making the correct choices. Unlike the selection of sunwear in a drugstore or optical store, our offices have not only many more colors of absorptive lenses, but we carry each of these colors in several densities as well. This is because the need for a glare protective lens of a certain darkness will vary with lighting conditions.

Visual Training
Many of our patients require not only adaptive devices for their vision loss, but training in how to better use their remaining vision. The complicated term for this is Neuro-muscular re-education.
It consists of eccentric viewing training for patients with central scotomas (blind spots), scanning and localization training for patients with peripheral vision loss, eye hand coordination training for patients who’s vision loss has effected this area, and often, after stroke or head trauma, specialized training for conditions known as neglect and postural or gait difficulties. All low vision evaluations look for any of these problems that often accompany vision loss, and training is provided as needed.

Other Services you might consider:
Social Services and referrals for Orientation and Mobility Training and Activities of Daily Living Programs are provided as indicated after your low vision examination.
Social Services can assist with both psychological adaptation to your vision loss, and with finding assistance for related difficulties you may be having. For example, if a patient is having housing problems, problems managing their home, problems with an employer, or problems with insurance or disability coverage, a social worker can help you navigate the bureaucratic paperwork jungle. In addition, more than a third of patients who lose vision become depressed from the loss. It is a normal reaction, but one that you can be helped to deal with. It isn’t necessary to suffer alone.

Rehabilitation Teachers
Rehabilitation Teachers help patients to adapt to difficulties in their work or daily living activities through the use of training and adaptive devices, many if not most patients with low vision can continue on their jobs, and continue to manage a home and remain independent.

Orientation and Mobility
Orientation and Mobility teachers more specifically work with any travel difficulties a low vision patient may experience. They can help if you have trouble seeing curbs or steps while walking, trouble crossing streets and seeing cars or traffic signals, or trouble finding your way around unfamiliar areas.
Often, an O&M teacher will work with a low vision patient who has had a telescope prescribed, to make sure they can use it safely and efficiently in the street environment.

Non Optical Aspects of Low Vision Care:
Other measures available include sunwear evaluations, lighting and environmental design consultations to maximize function in the patient’s real world setting, and visual therapy to enhance performance.

Who do you turn to when you have Low Vision?
The answer to this question may vary with the severity of your vision loss, and the part of the country you live in.

For those patients with Minimal vision loss, say 20/100 vision or better, you may find all the help you need with a local Optometrist who “dabbles” in Low Vision and has had minimal training in the techniques and devices available.

For patients suffering from moderate vision loss, you would be better served by a doctor who “specializes” in Low Vision. These doctors will have a wider range of optical and non optical devices to assist you, and typically see at least three low vision patients weekly. They should also have at least one CCTV in their office to demonstrate this technology.

For patients with severe vision loss, generally 20/200 or worse, or those having unusual types of vision loss such as field defects from R.P., Stroke, or glaucoma, you would be best served by someone who practices Low Vision Care on a full time, or nearly full time basis. These individuals generally have a much higher level of expertise, and a greater variety of assistive devices to help patients with very poor vision.