Web Version of NTU300 Random-dot Stereogram
(Screening Use)
Ai-Hou Wang, MD.
PhD.
Dr. Luke Lin and
Health Promotion Administration of Taiwan had set (1) distance visual acuity
and (2) random-dot stereopsis as criteria for preschool and school children
vision screening since 2000.
NTU300 is used for
random-dot stereopsis test. It stands for
In 2018
Dr. Wang and Computer Department of Universal Eye Center transformed NTU300
into cross-platform version which runs on all web browsers of Windows, Apple
iOS and Android systems. Hope it helps your clinical and screening works.
This is
the web link of NTU300
NTU
Random-dot Stereopsis Screening – Universal Eye Center
https://www.eyedoctor.com.tw/Stereopsis_Screening/
=== Description ===
NTU RDS
(Random-dot Stereopsis) Screening Test
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NTU RDS is a 4-alternative-forced-choice
(4-AFC) test.
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The answer is one among square, diamond,
circle or triangle.
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The chance of correct answer by guessing is
1/4.
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Dr. Lin set 5 consecutive correct answers
as pass criterion.
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The chance of 5 consecutive correct answers
by guessing is 1/1024, (1/4)5.
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Random-dot stereopsis test is effective in
detecting symptom-free small-angle esotropia and anisometropia.
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We implemented this test as online app to
share with you.
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The hidden shape is chosen randomly by the
computer. The tester does not know the answer and the test is thus a
double-blind one.
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Either correct or wrong answer is followed
with sound effect which may interest the young kids a lot.
(Clicking
on the speaker mark at right-upper corner of the screen will toggle sound
effect on/off)
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The interesting picture and sound effect at
the end would encourage the kids to try hard to pass the test.
=== Red/Blue Lenses
===
NTU300 was designed
to view with blue lens over right eye and red lens over left eye.
You may online shop
red/blue glasses. Try to search with keywords such as “3D glasses”、“stereo
glasses”、“red/blue glasses”…
The colors of
red/blue glasses should match with the colors of your computer screen to get
sharp 3D image.
Otherwise, the
right and/or left half-stereograms might crosstalk, i.e. the right eye might
see the ghost image of left half-stereogram or the left eye would see the ghost
image of right half-stereogram. Then the hidden 3D image will be harder to be
seen.
If this does happen
and it makes the subject unable to see the 3D image, you would misjudge and have
false positive result.
This is the figure
to test if the colors of the red/blue glasses and the computer screen match
each other.
Through blue lens
it should be blue/black horizontal stripes, and through red lens it should be
red/black vertical stripes, as clear and untainted as possible.
If there is any
ghost image, mostly the black strips look not so clean, it means the match
between the red/blue glasses and the computer screen is not so good. The hidden
3D image will then become harder to be seen.
Above is NTU300
random-dot stereograms for screening use.
There is another
general purpose NTU random-dot stereopsis test,
including tests for
300 sec-of-arc and 35 min-of-arc (2100 sec-of-arc) disparity-driven depth
perception
and motion-driven
depth perception.
Dr. Wang and
Computer Department of Universal Eye Center also made it into cross-platform
app to share with you.
The web link is
NTU Random-dot Stereopsis Test
– Universal Eye Center
https://www.eyedoctor.com.tw/Stereopsis/
