Cardiff
Contrast
Sensitivity Test
Cardiff products are CE marked
This test is designed for contrast sensitivity
measurement in toddlers and young children, and in older children or adults with
intellectual impairment.
The Value of Contrast Sensitivity
Contrast sensitivity is the ability of the visual
system to detect large but faint targets. There are some pathological conditions
that reduce contrast sensitivity without impairing visual acuity, and the test
will help in the identification of these conditions. However, reduced contrast
sensitivity and reduced visual acuity often occur together, so that some (by no
means all) children with visual impairment also have reduced contrast
sensitivity. Tests for the two functions are therefore complementary and
obtaining a measure of both will give a fuller description of visual deficits
than will one alone.
A child with visual impairment who retains good
contrast sensitivity will benefit from enlargement of tasks – he or she sees
large faint objects well. A child with an equivalent acuity but with reduced
contrast sensitivity has a much more severe impairment, and will not get the
same benefit from enlargement. Large objects as well as small objects are
difficult to see. So a measurement of contrast sensitivity can help determine
appropriate management of a child's impairment.
Treatment for visual deficits (including
amblyopia therapies) can result in improved contrast sensitivity sometimes in
the absence of increased visual acuity. Contrast sensitivity can therefore be an
essential tool in monitoring therapies. Some progressive eye conditions will
result in changes in contrast sensitivity, so that monitoring contrast
sensitivity alongside visual acuity (and other visual functions) may be
essential in determining progress of the condition.
 |
 |
| 6% Contrast
Level |
Occluding Glasses included with Test |
The Targets
Like its 'sister' test, the Cardiff Acuity
Test, the Cardiff Contrast Test uses vanishing optotypes.
The targets are drawn with a light band bordered
by two darker bands, each of half the width of the light band, all on a neutral
gray background; thus the average luminance of the target is equal to that of
the gray background. If the target lies beyond the subject's contrast limit,
it merges with the gray background, and simply becomes invisible.
The targets employed by the test are pictures,
all of the same overall size, but decreasing in contrast
between the light and dark bands. The contrast
sensitivity is determined by the faintest bands for which the target is visible.
The test covers 12 Contrast levels using three
Cards at each level (36 cards total) using the preferential looking technique.
These contrast levels start at 46% and decrease to 1 % which equates to
Sensitivity levels from 2.17 to 100.
When the Cardiff Contrast Test is carried out at
a distance of 50 cm the targets represent 1.9 cycles per degree (or 6/90,
20/300) and at a distance of 1 m the targets represent 3.8 cycles per degree (or
6/45, 20/150). At a distance of 25 cm the targets represent 1.0 cycle per degree
(or 6/180, 20/600).
Results from the test are presented in a manner
that is consistent with scoring of the Pelli-Robson Contrast Test for adults.
Clinical trials of the testing at Cardiff
University are being reviewed for publication.
Includes a pair of our Fun Frame Pediatric
Occluding Glasses and a pair of our Adult Occluding glasses.
| Card |
Picture |
Contrast (%) |
Contrast Sensitivity |
| A |
House |
46 |
2.17 |
| B |
Clock |
32 |
3.13 |
| C |
Boat |
22 |
4.55 |
| D |
Telephone |
16 |
6.25 |
| E |
Cup |
12 |
8.33 |
| F |
Car |
8 |
12.5 |
| G |
Fish |
6 |
16.67 |
| H |
Boat |
4 |
25 |
| I |
Clock |
3 |
33.33 |
| J |
House |
2 |
50 |
| K |
Car |
1.5 |
66.66 |
| L |
Train |
1 |
100 |

5667R Cardiff Adult & Pediatric Contrast Sensitivity
Test .......................................................
$1,650.00

5684R Cardiff Contrast Sensitivity
Test with Simplified Chinese & Traditional Chinese ..........
$1,650.00

5682R Cardiff Contrast Sensitivity
Test with French ................................................................
$1,650.00

5683R Cardiff Contrast Sensitivity
Test with Spanish ..............................................................
$1,650.00

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