A graduate student at the University of Waterloo has developed the first standardized chart to measure vision for reading in Arabic – a language spoken by hundreds and millions of people around the world.
I wanted to get a standardized chart in Arabic for testing my patients. I then discovered that we don’t have one.
The
chart
will
eliminate
the
potential
for
inconsistent
eye
results,
as
it
addresses
challenges
presented
by
the
language’s
complexity.
Dr.
Balsam
Alabdulkader,
a
PhD
student
at
the
School
of
Optometry
&
Vision
Science,
was
inspired
to
create
the
chart
after
returning
to
her
clinical
job
in
Riyadh,
Saudi
Arabia,
and
becoming
frustrated
with
what
was
available
–
or,
more
precisely,
what
wasn’t.
“For
my
masters
thesis
There are no standard texts in Arabic from which to draw sentences and there is no standard or accepted font in Arabic, said Dr. Susan Leat, who supervised the project. “Nor is there any standard method of determining the size of Arabic text, as there is in languages, such as English, that use Roman letters.”
When creating reading acuity charts, sentences are selected and tested for grade level, reading speed and other factors. Outliers are removed so that the sentences are consistent in their level of difficulty. The sentences are then arranged in a standard format, with sentences that gradually become smaller in a logarithmic scale, as the patient reads down the chart.
To determine font size, chart designers use the x-height (the distance between the baseline and the top of lower-case letters). This system works well for Roman letters. Arabic, however, is cursive, meaning the letters join together, and there is wide variation in letter height.
To
overcome
this
challenge,
Dr.
Alabdulkader
and
Dr.
Leat
used
a
single
repeated
sentence,
and
picked
one
letter
to
use
as
a
“yardstick”
to
determine
the
font
size
for
each
line
and
the
spacing
between
the
lines.
As there is no way to physically compare the Arabic print size to Roman letters, Dr. Alabdulkader and Dr. Leat empirically scaled the Arabic print against English using the reading performance of participants who could read both languages.
The resulting BAL (Balsam Alabdulkader-Leat) chart is available in three different versions. Each chart has fifteen print size levels that are labelled in logMAR and point size.
With help from WatCo, the University of Waterloo’s Commercialization Office, the two researchers have obtained copyright on the BAL chart and have now commercialized it through Precision Vision. It went on sale for the first time at the recent Academy of American Optometry conference in San Antonio.
Dr. Sue Leat was featured in this CTV story about the Arabic eye chart which she and PhD student Dr. Balsam Alabdulkader developed.
