Introduction
LEA
symbols, developed
by Lea Hyvärinen, MD, is the only complete set of visual acuity tests
for near and far distance vision for all patient groups 18 months and over.
The symbols are easy to recognize and accessories are available to create
a "play situation", making screenings for special populations
(non-English speaking and non-verbal children) much easier and more accurate.
The LEA visual test system is recommended as a reliable screening method
by; American Academy of Pediatrics, American Academy for Pediatric Ophthalmology
and Strabismus, American Academy of Ophthalmology and Prevent Blindness
America.
Product
Overview and Description
The LEA symbols are based on four symbols:
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Circle (sometimes
referred to as a ring or ball) |
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Square (sometimes
referred to as a block) |
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House (sometimes
referred to as a garage or dog house) |
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Apple (sometimes
referred to as a heart) |
These symbols are
widely used and recommended by professional eye organizations and pediatric
groups because they blur equally and are equally difficult to distinguish,
helping to eliminate guessing. The symbols are spaced so the distance
between the symbols on each line equals the size of the symbols on that
line.
Since the symbols
blur equally at threshold, this discourages a sense of failure on the
part of the child. When no longer recognized, the symbols transform into
circles (rings or balls). The child will still perceive that he or she
is answering "correctly" while the examiner can easily detect
the acuity threshold. This can be especially beneficial when testing visually
impaired children who are accustomed to experiencing failures in all vision
testing situations.
Product
Use and Procedure
The LEA Visual
Acuity System features several different types of tests and teaching accessories.
LEA Symbols Response Key and Flash Cards come with all LEA products with
the exception of the LEA puzzle (52-152) and Domino Cards (52-168). These
cards are used to familiarize the child with the symbols and offer nonverbal
and shy children an option of responding by pointing or matching.
CAT. NO 52-152 LEA Symbols 3-D puzzle set
The puzzle set is designed to train young children the concept
of the different symbols. One side of the puzzle is based on colors, since
children can match colors 6 months earlier than shapes. The reverse side
of the puzzle is black and white, allowing you to assess the child's ability
to recognize shapes without the help of color.
When the test symbols are introduced in a play situation with the puzzle,
children as young as 17 months may gain the ability to complete a visual
acuity test. The set can also be used as a response key for acuity tests.
The book My Sight is Important is included with the purchase of the LEA
puzzle. The book contains useful information on the development of vision
during the early childhood years.
The puzzle is not an acuity test or color test itself.
CAT.
NO 52-153 and 52-192 LEA Symbol Books
The Single
Symbol Book (52-153) is used to measure distant acuity and is designed
for children that find it difficult to complete a linear test. Each page
has one to four symbols of the same size. If the child can only concentrate
on one symbol at time, this test can be useful. It is important to remember
that acuity measured with single symbols is not comparable to acuity measured
with the linear test. It is usually 2-4 lines better than acuity measured
with a line test. Can be used to test near or distant vision.
Tests from 10ft
away. Test range 20/200-20/10.
The Crowded Symbol
Book (52-192) is also designed to measure distant acuity for those who
cannot perform a linear test. Each page has one optotype (symbol) surrounded
by symbols of the same size. The child must correctly identify the center
symbol. If the child cannot perform the Crowded Symbol Test, the Singe
Symbol test may be used. Can be used to test near or distant vision. Tests
from 10ft away. Test range 20/63-20/16.
CAT.
NO 52-151 and 52-193 Near Vision Cards
Near Vision Card 52-151
comes with a 16" non-stretch measuring cord attached to the chart
making it easy to obtain the correct distance. One side of the card contains
the linear test for Near Visual Acuity using wide-spaced symbols and the
reverse side contains crowded symbols for those children who are about
to learn to read. The crowded test should be used for children who are
learning to read, so that you can have an idea about the size of the text
the child can handle.
Near Vision Cart 52-193 is the pocket Near Vision Card (does not have
16" measuring cord). A quick way to find out if the child has a near
acuity within normal values.
CAT.
NO 52-168 LEA Symbols Domino Cards
A fun way to
accurately measure the visual acuity of children between the ages of two
and three.
The set contains 48 domino-like cards with a large symbol at one end and
a small symbol at the other end. The set is divided into three packs of
16 cards each. One pack has symbols of 3.2M and 0.8M. The next one has
symbols of 2.0M and 0.5M. The last one has symbols of 1.25M and 0.3M.
The back of the cards indicate symbol size, 6 meter equivalent, 20 foot
equivalent and decimal visual acuity value at a 40cm test distance.
Domino cards can also be used to train an amblyopic eye at any age.
CAT.
NO 52-114, 52-148, 52-149 and 52-150 LEA Charts for Distance Testing at
10 Feet
52-114 is a
translucent chart measuring 9"X14". It is designed for use in
an illuminated cabinet (see illuminated cabinets) but can be wall mounted.
The illuminated cabinets insure that you have the recommended uniform
illumination for reliable vision screenings.
Contains crowded symbols for older children who are beginning to learn
to read.
52-148 is a translucent
chart measuring 9"X14" that features wide, fixed spacing, which
allows the use of a mask (included) to isolate optotypes. It is designed
for use in an illuminated cabinet (see illuminated cabinets) but can be
wall mounted. The illuminated cabinets insure that you have the recommended
uniform illumination for reliable vision screenings. It is important to
remember that acuity measured with single symbols is not comparable to
acuity measured with the linear test. It is usually 2-4 lines better than
acuity measured with a line test. This chart will be easier to use for
younger children who have not began learning to read.
52-149 is a 10
Line Test using crowded symbols. Folds to 8.5"X17". Has hole
for easy hanging.
52-150 is a 15-Line
Test for screening children who may be old enough to memorize the symbols
in a screening situation. Features 3 sets of symbols on lower lines to
avoid memorization. Folds to 11"X17". Has a hole for easy hanging.
Distant charts
are conducted at a distance of 10' with the child's heels being placed
at the 10-foot line.
Before testing
begins, establish the names of the symbols with the child. The child can
decide the names of the symbols. Remember, the child may change the names
during the test. For example, if the larger symbol was called a "house"
the smaller one may be called "dog house" and "apple"
may become "berry", etc.
Start with testing
both eyes first before testing each eye separately. This allows the child
to become familiar with the testing situation.
Each LEA test comes
with complete instructions.
To view the instructions online, go to www.lea-test.fi.
Choose Vision Test and go to the Instructions Section
Features
and Benefits
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Symbols blur equally
at threshold |
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Several testing
methods to allow screening of children as young as 19 months |
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Charts available
for line tests, crowded symbols and single symbol test |
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Use of symbols help
reduce problems with language barriers. All symbols are easy to name,
sign or point to on the key card or with the help of separate response
cards |
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Symbols are equally
recognizable and spaced so the distance between symbols on each line
equals the size of the symbols on that line and the separation of
the rows equals the height of the symbols in small rows. |
Frequently
Asked Questions
| Q: |
How
do I know when to refer a child for a complete eye exam? |
| A: |
Visual acuity is
recorded as the last line on which at least 3 of the 5 symbols are
identified correctly, except when a line is read twice, then 4 out
of 5 are required. You should follow guidelines that have been established
by your local state or county. If no guidelines have been set, check
with a local Pediatric Ophthalmologist or Optometrist. Prevent Blindness
America has referral guidelines of 20/50 for children 5 and younger
and 20/40 for children 6 and older. Any behavior, complaint or appearance
of an eye problem should be referred for further evaluation. You can
find out more about Children's Vision Screening and trainings offered
by Prevent Blindness America at www.preventblindness.org
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| Q: |
If
the child wears glasses, should they be screened with the glasses
on? |
| A: |
Yes. If the child
wears the glasses for Distance Only, the glasses should be worn
for the DISTANCE test only. If they are worn for Reading Only, they
should be worn for the NEAR test only. Multifocal wearers should
be tested through the proper lens area for the appropriate distance.
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| Q: |
How can I be sure the child knows when they should be wearing their
glasses? |
| A: |
Ask the child "trigger
questions"- Do you wear your glasses to see the chalkboard? (DISTANCE)
Do you wear your glasses just for reading? (NEAR) Do you wear your
glasses all the time? (Both Distance and Near). If a child fails the
test with glasses, you may ask them to take off the glasses and view
the chart again (or visa versa). Ask the child if the symbols are
clearer now. This may help insure they are wearing their glasses for
the right purpose.
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| Q: |
On
average, how many children should be referred? |
| A: |
An estimated one
in four school age children and one in twenty preschoolers have a
vision problem. If you find you are over referring, it is recommended
that you rescreen referrals.
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| Q: |
There
are so many charts to choose from. How do I know what I need? |
| A: |
Check with your
supervisor or other School Nurses to see if there are guidelines in
your state. If not, call your School Health Representative who can
explain the different charts and assist you in choosing what will
best meet your needs. You can also visit the LEA web site at www.lea-test.fi
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Technical
Specifications
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52-152 LEA Puzzle
7" x 7" x 7.5" |
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52-153 and 51-192
Single Symbol and Crowded Symbol Book 13- 5" x 5" pages |
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52-151 Near Vision
Card with non-stretch 16" measuring cord 8" x 10" x
13" |
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52-193 Pocket Size
Near Vision Card 3.75" x 6.25" |
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52-114 and 52-148
Distant Charts 9" x 14" |
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52-149 10 Line Distant
Chart 15.5" x 17.5" (unfolded) |
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52-150 15 Line Distant
Chart 17.25" x 24.5" (unfolded) |
Articles / Sales Brochures
/ Manuals
Click here for more
information on LEA symbols at www.lea-test.fi
Click
HERE to view the results of Phase 1 of the VIP study as printed by
the American Academy of Ophthalmology. The article is titled, "Comparison
of Preschool Vision Screening Tests as Administered by liscened Eye Care
Professionals in the Vision in Preschoolers (VIP) Study".
Warranty
All products School Health
offers are backed by a one year satisfaction guaranteed warranty.
Reimbursement
The American Medical Association
shows code #99173 for reimbursement
purposes. This code is titled "Screening test of visual acuity, quantitative,
bilateral".
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