This document discusses various contrast sensitivity tests used in vision testing. It describes several grating and letter-based contrast sensitivity charts, including the FACT chart, Pelli-Robson chart, Vistech tests, and Cambridge Low Contrast tests. It provides details on test administration and scoring for many of these assessments. The document also discusses computer-based contrast sensitivity testing and considerations for contrast calibration of video displays used for testing.

1. CONTRAST SENSITIVITY
(CHARTS)
Jagdish Dukre

2.  no international recommendation on how contrast
of visual acuity charts should be defined.
 Therefore there are differences in the contrast of
tests of different manufacturers.

4.  Test results are marked on the recording sheet at the level
used (see example below) going along that level toward
the right until the visual acuity value, measured at that
contrast (A’ at 1.2%, B’ at 2.5%), is reached.
 If the person’s visual acuity was 20/20 (6/6, 1.0), the line
connecting these three points, A’, B’ and X, depicts the
slope of the contrast sensitivity curve of this person.

6. Cambridge low contrast
gratings
 It is a rapid and simple screening test for contrast
sensitivity.
 Performed at a distance of 6m.
 It comprises of 12 pair of plates consisting of
stripes of varying contrast.
 First one is for demonstration and rest are for the
proper testing and are numbered from 1-10.
 The plates are changed sequentially starting from
plate 1 till the patient fails to respond.

7. Cambridge low contrast
g ratings
 Then a new series is begun starting 4 plates prior to
where the patient failed to respond.
 Four such series are completed and the score of
each series is noted (numbered as per the number
of plate read) and added.
 The final total value is converted into contrast
sensitivity from the provided table.

8. Functional Acuity Contrast Testing
(FACT)
 FACT charts were developed by Dr. Arthur
Ginsburg.
 FACT comprises of a chart with sine-wave gratings
of varying contrast as well as varying spatial
frequencies.
 It is an accurate and comprehensive grating chart
that tests functional visual acuity.
 This test is performed at a distance of 10 feet.

9.  The chart tests five spatial frequencies (sizes) and nine levels
of contrast.
 The Contrast varies in a row, decrease from left to right.
 And the spatial frequencies increase as one move down the
various columns from top to bottom

10.  The patient determines the last grating seen for each row (A,
B, C, D and E) and reports the orientation of the grating: right,
up or left.
 The last correct grating seen for each spatial frequency is
plotted on a contrast sensitivity curve.

11. Vistech VCTS 6000 and 6500
Contrast Sensitivity Tests
 There are two Vistech CS tests; model 6000 is used to
test near (i.e., reading distance) sensitivity at 40 cm (16
in), and model 6500 tests far sensitivity (3.05 m = 10
ft).
 Both tests use charts with 5 rows of sine-wave gratings.
 The rows increase in spatial frequency from the top to
bottom of the chart, and on each row the gratings
decrease in contrast from left to right.

12. Vistech VCTS 6000 and 6500
Contrast Sensitivity Tests
 The observer’s task is to indicate each grating's
orientation (leaning left, vertical or leaning right);
 The lowest contrast grating determines the sensitivity
score for that spatial frequency.
 The sensitivity at each spatial frequency can be used to
plot a csf for the observer, and can also be compared to
the age norms provided for the test.

13. Vistech VCTS 6000 and 6500
Contrast Sensitivity Tests

14. CSV-1000E
 It is widely used in the
world
 This test provides four rows
of sine-wave gratings
 The test distant 2.5 meters,
 Gratings test the spatial
frequencies of 3,7,12,and 18
cycles/degree $250.00

15. CSV-1000E
 Useful for the evaluation of ocular disease
(particularly cataracts, glaucoma, optic neuritis,
diabetes, and macular degeneration), contact lenses,
and refractive surgery.
 For cataract documentation, a functional acuity score
can be obtained directly from the test scoring sheet.
$250.00

16. CSV-1000-S
 This test presents standard visual acuity from
20/15 to 20/200, two rows of spatial frequencies
(6 and 12 cycles/degree) and a real-world
driver’s scene.
$250.00

17. CSV-1000-S
 Used for in or out of office screening and for
cataract evaluation
 The test is very useful for cataract
documentation as it provides a standard acuity
score, a functional acuity score and a real-world
simulation.
$250.00

18. CSV-1000 LAN C
 Provided the same tests as
standard CSV-1000-S
expect that acuity is
presented in landolt c
format
 Useful when patient cant
read English alphabet

19. CSV-1OOORS
 The CSV-1000RS test face is used
widely for screening refractive surgery
patients.
 The test presents ETDRS LogMAR
acuity from 20/10 to 20/100 and one
row of spatial frequency at 12
cycles/degree.
 The patient can be easily screened in
the examination chair for ETDRS acuity
and contrast sensitivity.
 If a contrast sensitivity deficit is found,
retesting the patient with all four
spatial frequencies using the CSV-
1000E is recommended.

20. CSV-1000 CVA
 Used to evaluate both
contrast sensitivity and
low contrast acuity
 Contain 3 contrast
levels

21. CSV -1000 – 1.5 cpd
 It is special test designed
specifically for food and
drug administration clinical
trials
 Recommended test distance
of 8 feet,
 The gratings test one spatial
frequency of 1.5
cycles/degree.
$250.00

22. Contrast sensitivity view in
testers
 Sine-wave grating contrast
sensitivity testing is
available in view-in testers
 The advantages are that
they eliminate the need to
control room light levels
and can be used in small
test space

23. Pelli-robson letter contrast
sensitivity
 It is simply of quickly measured and provides a
reliable measurement of low spatial frequency
contrast sensitivity ( 0.5 – 2 cycles)
Method:
 Sit the patient 1m from the chart with his or her
correction if needs
 Occlude one eye or with both eye
 With both eyes result high with 0.15 log units

25.  The patient is asked to read the alphabets starting
from left hand corner,
 when he fails to respond several seconds are given
to him to retry and guess the alphabet.
 The score of the test is recorded by the faintest
triplet out of which at least 2 letters are correctly
identified.
 The log CS value for this triplet is given by the
number on the scoring pad nearest to the triplet,
either on the left or the right side.

26.  Record the contrast sensitivity score in log units
RReessuullttss::
 For patient 20-50 years old monocular contrast
sensitivity should be 1.80 log unit
 Patient less than 20 years and older so years
monocular contrast sensitivity should be 1.65 log
units

27. Most common errors
 Not allowing patient at least 20 second
for letters to become visible
 Not pushing patient to guess
 Illumination is poor

28. Mars Perceptrix Letter Contrast Test
 The Mars Perceptrix contrast test indicates the
lowest contrasts your patients can perceive.
 With the Mars test, it is the contrast, and not the
letter size, which diminishes from the beginning to
the end of the chart.
 The letters are large, insuring that most patients,
even those with low vision, can see them.
 The Mars Perceptrix test comes with 3 low contrast
charts, instructions and storage pouch.

29. Mars Perceptrix Letter Contrast Test
$395.00
$150.00 each

30. Mars Perceptrix Numbers Contrast Chart
$395.00
$150.00 each

31. Adult Near Contrast Test
 This adult near vision low contrast test features
both ETDRS Format and Continuous Text in
100%, 25%, 10%, 5%, and 2.5% contrast level.
 Continuous text letter sizes range from 6/30 to
6/6 equivalent in each contrast level.
 ETDRS format letters sizes range from 6/120 to
6/3 equivalent in 17 increments for each contrast
level.
 The near vision contrast booklet contains 7 pages
measuring 15.8 cm x 15.8 cm.
 testing distance : 40 cm

32. $140.00

33. Sloan Letter Low Contrast Flip
Char t
 Easily measure, record, and detect changes in the
transfer of visual information when the change affects
only visual acuity at low contrast levels.
 Charts include the following contrast levels: black,
25%, 10%, 5%, 2.5%, and 1.25%.
 Each chart includes recording forms and instructions.
6 pages, 8.25 cm x 22.9 cm.
$95.00

34. Pacific Acuity Test
 The Pacific Acuity Test is a vanishing optotype test
 It is designed with opposing figures to provide a
simple forced-choice testing format.
 It is appropriate for nonverbal children and
individuals with developmental disabilities who are
unable to respond to standard optotype recognition
tests.
 Each card has two figures, a simple face, and an
opposing oval target of the same overall size but
with interior details that allow discrimination from
the face at the threshold of acuity.

35. Pacific Acuity Test
$680.00

36. Pacific Acuity Test
 The full test kit consists of 18 cards with two cards
at each level.
 The cards at each acuity level have a different
position of the face target compared to the opposing
oval figure.
 Each card can be presented at either 50 cm or 1
meter
 But the 1 meter test distance is recommended for
greater accuracy and comparison to distance visual
acuity tests.
 The test range from 20/400 down to 20/20 allows
for testing a broad range of visual acuity

37. Cardiff Pediatric Low Contrast Charts
 Cardiff Low Contrast Charts are designed to measure
contrast sensitivity in
developing toddlers and young children,
as well as in older children and adults with intellectual
impairment.
 Test targets are pictures of the same size that
decrease in contrast between 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 3 cards at
each level (36 cards total) using the preferential
looking technique.

38. Cardiff Pediatric Low Contrast Charts
 Contrast levels begin at 46% and decrease to 1%, which
equates to sensitivity levels of 2.17 to 100.
 Cardiff Low Contrast Chart test is conducted at
 distance of 50 cm, the targets represent 1.9 cpd (6/90)
 distance of 1 m the targets represent 3.8 cpd(6/45).
 distance of 25 cm the targets represent 1.0 cpd (6/180).
$1,650.00

39. Hiding Heidi Low Contrast Face
Test
 Visual communication is the most important
communication method during the first year of
life.
 The ability to detect objects of low contrast is an
important component of the visual system.
 For example, facial expressions are mediated by
faint shadows and changes in the contours of the
mouth and eyes.

40. Hiding Heidi Low Contrast Face
Test
 Determining the levels of contrast
that an infant can detect helps
provide baseline data for evaluating
future changes.
 For example, deviations from usual
behavior may indicate disorders that
leave vision at high-contrast levels
unaffected.
 Four cards printed on both sides in
the following contrast levels: black,
25%, 10%, 5%, 2.5%, and 1.25%.
 Cards are 23 cm x 23 cm
$95.00

41. Computer/Video Contrast
Sensitivity Testing
 Computer/video grating tests offer
the highest degree of test flexibility
in terms of technique, target
configuration, and spatial
frequencies.
 The disadvantage to to these
systems is that they are relatively
costly and complex.
 They also require careful
consideration and monitoring of
contrast calibration of the video
display.

42. Enhancement game
 The enhancement game is the first game that
allows training of low contrast vision in play
situation.
 It is used for young children & multihandicapped
persons.
 It is useful to enhance and train visual function at
low contrast levels in amblyopic eye.

44.  The Pelli-Robson”* variable contrast letter chart consists of 16 groups of
three letters (a ‘triplet’) arranged on eight lines.
 The contrast of each triplet reduces in logarithmic steps. As the letter size
(spatial frequency) is fixed and the contrast is varied the test procedure is
more like conventional contrast sensitivity measurement.
 As the patient reads down the chart the letters reduce in contrast and in
contrast sensitivity terms they move up Figure 2 until the detection limit
is reached near the peak’of the CSF.
 In the manufacturer’s description and in most reports the test is
administered at one metre and would be expected to measure sensitivity
at approximately one cycle per degree (fundamental frequency) but
higher harmonics (3, 5 and 7 c.p.d.) will also be detected.
 We suggest that the test may be better at three or four metres, where the
fundamental spatial frequency tested is approximately three or four
cycles per degree45 and therefore nearer the peak of the CSF.
 In the original description of the test, the last triplet where at least two
letters are read correctly is scored.32

45.  To improve reliability, Elliott and colleaguesg2 suggested scoring correct
a call of ‘C’ for ‘0’ or a call of ‘0’ for ‘C’.
 To further improve reliability, theyg3 then suggested scoring each correct
letter as 0.05 units.
 At one metre, the average Pelli-Robson score should reduce from about
1.90-l 85 at age 20 to 30 years to about 1.80-l .75 at age 70
years.5g~94~95
 If a different distance such as three metres is used, ‘normal’ values will
need to be established.
 Lighting requirements of 85 cd/m2 (acceptable range 60 to 120 cd/m*)
can require some manipulation to get this large (64 x 85 cm) chart
 evenly lit.
 Pelli-Robson charts have proven to be quick and reliable in clinical
practice and to have significant uses in the description of visual
performance.
 Studies by a number of workers have demonstrated that the Pelli-Robson
chart can detect a reduction in visual function in patients

46.  The two main types of CS charts are in use;
charts that show gratings, such as the
Functional Acuity Contrast Test (FACT)
charts (as it is used in the OPTEC Functional
Vision Analyzer, Stereo Optical, IL, USA),
[8] and charts that show letters, either with
altering optotype size at constant contrast
settings (e.g., 5 or 10% contrast) or
optotypes that are always of the same size
but with decreasing contrast levels, such as
the Pelli Robson