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Getting
the Most Out of Your
Low Vision Experience - LOW VISION -
"THE RULES OF THE GAME"
by: Southwest Low Vision 1-888-534-4321
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For persons who have Macular Degeneration and other eye diseases such
as diabetic retinopathy or glaucoma, the low vision process is geared
to help with functional vision tasks and aimed at persons who have reduced
vision in both eyes. These individuals need help with tasks such as
reading small print, writing letters or checks or filling out forms,
or seeing faces of grandchildren.
Because
everyone's vision is different, and their visual tasks and needs vary,
low vision rehabilitation should be seen as a joint effort between the
patient and the professional, and even sometimes a family member or
two. It should also be seen as a process because there usually is no
"quick fix" or "single pair of glasses" that will
do it all. Instead, depending on the severity of the vision loss it
may be a ten-step process that will require a lot of patience moving
from step 1 to step 2 to step 3 etc. There is no "jumping"
from step 1 to step 10. Patients should expect to view their low vision
rehabilitation as a slowly improving continuing process that will be
with them for the rest of their lives. As people's needs and vision
changes, low vision rehabilitation will also change to help adapt and
make improvements so that they can maintain as much of their "quality
of life" as possible.
Historically,
persons were referred to a low vision center when their vision reached
the 20/200 level or "legal blindness". Today, we realize that
it is far better to refer somebody for low vision services when they
have a mild to moderate vision loss in each eye. For instance, if a
person's best seeing eye is in the range of 20/50 and they are beginning
to have trouble spotting small print type, sometimes education about
a good reading task light and a stronger bifocal lens can do the trick
for such a patient. If vision continues to worsen, this patient may
return to the low vision specialist for a "booster session",
having already adjusted to using low vision devices and making modifications
in their current use of low vision aids.
Unlike
medical eye examinations, the low vision process can take many hours
of directions and hard work by the patient - not only during the examination,
but also afterwards when he or she is "practicing" many times
each day following the exam to gain maximum benefit. That is, the patient
needs to "take ownership" in this process. "Take ownership"
is a phrase we use in psychology. It means you are ready to take responsibility
for whatever may be asked of you to get the maximum improvement. Yes,
the Doctor may prescribe things for you but you must work together with
the Doctor or the low vision professional to come up with solutions
that work best for your situation. You cannot "sit back" and
expect the Doctor to do it all.
Another
misconception about low vision aids is that there is going to be "one
pair of glasses" or "one magic device" that will do it
all for you. A typical low vision patient may use 5 or 6 different items
to help with his or her visual tasks depending on whether he or she
is reading small print or large print, reading at home vs. reading in
a dark restaurant, or reading a price tag in a store. Other aids may
be used to view grandchildren's faces and even high tech items such
as CCTV's, computers, and head-borne electronic goggles help make today's
low vision patient independent and successful in whatever he or she
wishes to accomplish.
There
are some rules that govern the use of each low vision device and you
must know the rules and educate yourself about them - both the positive
gains and the negative side effects. Otherwise, you will not be approaching
each device with a realistic expectation of what it can do for you.
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| Rule
#1 |
When
using a hand held magnifying glass, you need to know that these lenses
come in different powers or strengths. It is important to keep in mind
that as the power of the lens gets stronger, the diameter of the lens
gets smaller. Another way to say this is, the larger the lens, the weaker
the power will be. Many people ask for a large lens that will cover
a wide area, or would cover the entire page - obviously this is not
possible because as the lens gets stronger it will get smaller and smaller.
The
lens will also have to be held closer to the paper as it gets stronger.
Often when persons use very strong lenses, this distance from the paper
can become frustrating because if the lens is moved slightly it may
go out of focus. It is hard to maintain an equal distance from a piece
of paper unless the entire paper is flat and you have a steady hand.
This is one of the reasons why a stand magnifier (a magnifier with little
legs on it) is often chosen. The legs on the magnifier are preset with
the correct focal distance from the paper and the person can easily
move this stand magnifier across the paper to read. When using a hand-held
magnifier, however, it is important that the person does not look through
their bifocal lens to read. When using a stand magnifier, it is important
that they look through their bifocal. Yes, there are many rules to the
low vision process and sometimes having another family member or friend
go with you on an appointment can help "take notes" of these
many rules in using low vision aids.
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Rule
#2
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Just
to make matters more confusing, magnifiers come in two different types
of measurements. The common or layman term, often used in describing
the power of the lens, are known as 2x or 3X or 4X. These are commonly
known as 2 power, 3 power or 4 power. You may have noticed this when
looking through a catalog of low vision devices for these measurements.
However, you may also have noticed for the same magnifier a description
labeled +8 diopters, +12 diopters or +16 diopters respectively. What
does this mean?
An
easy way to remember the true measurement or diopters in a lens is as
follows: Multiply the power, for instance 2X by 4 to determine the diopters,
in this case equaling +8. 3X would equal +12 diopters, 4X would equal
+16 diopters, 5X would equal +20 diopters and so on. When you convert
the power of the lens to diopters, you are helping to make an "apples
to apples" comparison of all magnification lenses. Some lenses,
for instance, may come in a reading half-eye in a power of +6, +8, +10,
+12. People mistakenly call these reading glasses 6 power, 8 power,
or 10 power, which they are not.
To
make things even more confusing lenses manufactured in Europe have had
a different standard although there is currently a strong proposal underway
to make all lenses, U.S. and European, equivalent. Currently, lenses
made in England or Germany such as Coil or Eschenbach brands, use the
following formula: the power of the lens multiplied by 4 just as in
the US lens, then subtracting 4 from the total. For instance, a 4X lens
in US diopters would be +16, in European it would be +12. A 6x magnifier
would be +24 in US and +20 in European. Sometimes you may not know where
the lens is manufactured so two different 4X magnifiers may be the same
or may be much different in strength if you cannot determine the number
of diopters.
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Rule
#3
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No
matter what lens is selected by the low vision person, it is only as
good as the task light that is available to illuminate the printed material.
Low vision persons should consider investing in a good quality task
light regardless of the optical device they use - now and in the future.
When selecting a task light, first determine where you want to sit when
doing most of your reading - in your comfortable chair or at a table
or desk?
Task
lights are characterized by having a swing arm or an adjustable gooseneck
configuration where a person can pull the light down close to their
reading material. Ideally, the light should be placed below eye level
to reduce glare, and if using a hand held magnifier, the lamp should
be angled so that the light goes between the magnifier and the page
and not through the lens. It should also have a hard cover or shade
so that the light gets focused only on the task. The lamp should be
placed over the shoulder of the better seeing eye when reading in a
chair or in bed. When reading at a desk or table, avoid having the task
light directly in front of you since light will "bounce" off
the paper towards your eyes. Try to angle the lamp so the light is coming
more from the side, and then bouncing away from you.
For persons who read for a long period of time, you may want to consider
using florescent bulbs. Many new high quality lamps offer a combination
of several florescent bulbs within one lamp for a full spectrum of light-also
called daylight bulbs. (Daylight lamps can also help to reduce the strngth
of magnification needed by 1 or 2 power.) There are also florescent
bulbs that screw into a standard socket. The low heat, full spectrum
bulb can emit 100 watts of light, yet only take 15 watts of power. They
are low heat, and also rated to last 10,000 hours.
Incandescent
bulbs are most popular; however, many people feel that they need a high
wattage bulb to do the job. This is not true, and can be a hazard because
some lamps are only rated to hold a 60-watt bulb. If a person tries
to use a 100-watt bulb, he or she can cause a fire. Task lights that
use a halogen bulb provide the most illumination, however there is a
lot of heat emitted by the bulb, and these task lights usually cause
a "hot spot" on the page with uneven illumination.
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Rule
#4
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Many
persons say "I'd rather not have to hold something in my hand to
read. Isn't there a way to make a stronger bifocal lens or a pair of
reading glasses to help?" The answer is yes - but here is where
the next rule comes in. Reading lenses, whether in a bifocal or in a
pair of low vision reading glasses also come in different powers or
strengths - the higher the power or strength of the lens, the closer
you must hold the reading material.
Most
people have been reading at a comfortable distance of approximately
18 inches for most of their life, now their low vision specialist says
that they must use +8 magnifying reading glasses and must hold the reading
material 5 inches from their glasses. People exclaim - "If I have
to read that close, I am not going to do it! That is way to close!"
Unfortunately there are some optical laws of science which are a draw
back to using stronger and stronger lenses and this rule in low vision,
often called the 40 inch rule, is as follows: the formula 40 inches
divided by the power of the lens equals the focal distance you must
hold the material. Well let's take an example. If you had been reading
with bifocals that were a power of +2.00, you have been reading at a
distance of 18 or 20 inches. Now that you have Macular Degeneration
or low vision and need a more powerful lens, perhaps a power of +8,
you take 40 inches and divide by 8, which gives you a focal distance
of 5 inches. Some persons are not able to see regular print even with
a power of +8, so they must go to a stronger lens, let's say a power
of +10. Now, 40 inches divided by 10 means you must hold the material
at 4 inches. Are you getting the idea? Many people also state that when
they first try this type of lens, they feel a "pulling" or
"tugging" on their eye, which is uncomfortable and unfamiliar.
Other people even state that they feel nauseous or it makes their stomach
upset because the lens is so strong. Even though this is a common reaction,
it is one that must be overcome slowly but surely in order to be a successful
user of this type of low vision device. It can be done - no one said
it was going to be easy - or maybe you said in your own head (expectations
"this will be easy and I will find a lens that will help me read
again!") Unfortunately again, low vision is a slow and sometimes
difficult process of adjustment and cannot be hurried along. With much
patience and forbearance come little steps towards success.
There
are also other options that people may choose. For instance maybe using
both reading glasses and a hand held magnifier so that the power in
the lens does not need to be as strong, so that the reading material
can be held farther away, then using a hand held magnifier for smaller
print types when needed. For persons with a severe vision impairment
who need lenses that are very strong, they may have to have a special
lens made in a pair of glasses which range in the power of + 20 to +40.
These types of lenses, only available through low vision Doctors, have
a very close working distance of 1 to 2 inches from the eyes. There
are also some new telephoto reading glasses which allow a person to
read at a distance of 3 inches instead of at 1 or 1 1/2 inches, yet
these type of lenses take a lot of patience and training in their proper
use. Many people who find themselves in this category often choose to
also look toward electronic magnification such as a closed circuit television
reading machine (CCTV) to help read printed material and to write letters,
checks or forms. The advantage of using a closed circuit television
reading machine is that a person can sit comfortably, at a working distance
of 12 inches to 16 inches, with much stronger powers than available
in an optical lens. These systems, which project reading material onto
a TV screen or monitor, can go from 3 X to 45 X or sometimes 60 X so
that a person can take a phone book, for instance, and place the book
on the tray and see the letters on the screen at one inch high or five
inches high depending on how they turn the dial. The letters can also
be viewed with much more contrast, using white letters on a black background
or black letters on a white background, and some new machines also have
different color combinations which are easier to detect for some. Now
you can bring this type of equipment with you to the grocery store or
the restaurant, in the form of portable CCTVs (see Amigo or Nemo), which
are miniaturized versions of the table-top CCTV. There are also several
other optical tools in your "tool box" to help you read a
price tag in the store or a menu in a restaurant. Many of these items
are specialty items such as a magnifying glass with a built in light,
just for this type of situation.
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Rule
#5
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For
persons with Macular Degeneration, there may not be any distant prescription
glasses or contact lenses that would improve vision acuity. So, how
can a person improve their distance viewing? Either by getting closer
to the objects they want to see, or by using some type of telescopic
lens. There are many varieties of telescope lenses available through
low vision centers and low vision catalogs, but if you have never used
a telescope before there are some things you should keep in mind. Telescopes
also come in different powers or strengths, for instance many persons
may start at 3X or 4X (referred to as 3 power or 4 power). 6X, 8X, and
10X powers are also available.
A
telescope by its characteristics is always a two-lens system. That is
the lens that you look through is the lens closest to your eye, the
second lens is the lens that is furthest from your eye, or "sticking
out" near the front of the telescope. As the telescope power or
strength gets stronger, the area or field of view gets smaller. So,
with stronger lenses smaller details can be seen, yet the trade off
is a smaller viewing area. This is a very important rule when considering
using a telescope because again like a magnifying glass, he or she may
be frustrated at only seeing a small area at one time and reject using
a telescope.
There
are so many varieties of telescopes in the low vision market today.
Some of them are hand-held telescopes that are quite small, maybe 1
1/2 inches to 2 inches long, and can be carried in a pocket or purse
or worn around your neck on a strap like a whistle. Some of these type
of hand-held telescopes can also be mounted into a pair of glasses so
that the person, with help from a professional, can utilize the scope
in their best seeing eye (that means they would only use the telescope
for one eye) and have the scope drilled through the lens of the glasses
so that the telescope does not have to be held in the hand, but can
be worn on a pair of glasses for TV viewing or other types of viewing
for a longer period of time. There are also other companies who make
monoculars or binoculars (one or two eyed telescopes) that you can wear
like a pair of glasses for viewing distant objects.
Probably
the greatest request for these type of systems is for watching TV; however,
some persons are frustrated by the small field of view and often cannot
see the entire TV screen at one time when using this type of telescope,
especially in the stronger powers. Some use telescopes very well however
and with proper training and guidance, it can be a very important tool
in your low vision toolbox. Other uses for telescopes include seeing
the blackboard in school, the minister's face at church, viewing a movie
or slides, seeing a street sign or bus sign, the clock on the wall.
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Rule
#6
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Probably
the hardest low vision visual task to help someone attain in low vision
is the intermediate distances such as seeing music on a music stand,
playing cards where a person needs to see the cards laid out on the
table, or other tasks such as seeing the computer screen or the keyboard.
There are special reading telescopes that allow a person to do some
of these tasks; however, the rule here also applies as in distance telescopes
that the stronger the telescope, the smaller the viewing area. Many
persons stated that even though they could see one note at a time on
their music sheet, it is too difficult to use to move along and follow
a line of music. Some distance telescopes also can be used as intermediate
telescopes simply by turning the outer lens to create this short focal
distance. Many people have success in using a telescope for such tasks
as seeing through a glass case in a museum for instance or being able
to see fish in an aquarium or small animals or vegetation in a terrarium.
There
has also been a lot of enthusiasm about the new Occutech Auto-Focus
telescopic system, recently seen on CNN, which can be mounted on a pair
of glasses. This lens system which is used for one eye and comes currently
in a power of 4X automatically focuses for reading, intermediate, and
distant tasks which takes away some of the frustration of constantly
having to refocus the telescope.
Finally,
there are a few new high tech video magnification devices that can be
worn like glasses, or a camera system to help see even better than telescopes.
These systems, one called Jordy and another called Flipper Port, allow
a person to see TV, and many distant objects. The advantages of these
systems are that the level of magnification can be changed, from small
to large to very large, with the click of a switch. These low vision
aids can help to make the low vision person more independence, bring
a new quality of life, and allow a person to be as independent as he
or she wants to be.
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Southwest Low Vision 1-888-534-4321
520-297-0027
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