Celeste van der
Merwe
Optometrist, BOptom
(UJ)
vision deficiency through an Ishihara
test (a plate of coloured dots making
up a number). This test pinpoints
exactly what colours are outside your
scope of vision and to what degree.
Next is a case2 with multi-coloured
lenses that will be adjusted in front of
your eyes in a trial frame. The Ishihara
test is then repeated and the changes
noted down. This test will be repeated
until a specific colour is found that
optimises your colour vision. From
there on lenses are ordered either
as spectacle lenses or contact lenses
(only the portion covering the pupil is
coloured in the contact lens). Again it
is important to state that these lenses
will only enhance your colour vision
perception, it will not cure your colour
vision deficiency.
What if your colour vision is normal
but you tend to feel fatigued from
reading and computer use? Or your
child is a slow reader or has learning
difficulties like dyslexia? Coloured
lenses can again help to save (if not
save then at least improve) the day!
Using the aforementioned
techniques, a coloured lens can be
identified to relieve visual fatigue.
When reading a book, the spacing
of letters can cause your eyes to get
tired due to pattern glare. Pattern
glare is the discomfort that arises
from viewing repetitive patterns like
printed text. Symptoms of this can
include eye strain, letters dancing
around, letters appearing washed out,
inability to concentrate on the reading
material for prolonged periods of time,
sensitivity to light and difficulty with
focusing.
One of the FDA-approved lens
systems used is ChromaGen™ lenses
for the management of reading
disorders through spectacle or contact
lenses. These lenses incorporate
different colours that make viewing
printed text more comfortable for
dyslexia sufferers. As visual dyslexia is
thought to be a problem of the wiring
circuit of the information pathways
between the eyes and the brain,
these lenses can help to process the
information more easily, because the
picture being viewed is now presented
to the brain in a different way.
Studies performed by specialist
optometrists from ChromaGen™
showed a minimum improvement of
45% in the reading performance of
children. Albeit that colour lenses as
June/July 2014•
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