
Metropsis: contrast sensitivity function test
The Contrast Sensitivity Function test measures a range of spatial frequencies.
Contrast thresholds can be measured using a choice of standard
psychophysical procedures. A flexible range of options are provided,
based upon existing
contrast sensitivity function literature and customer requests,
designed to meet the needs of most researchers measuring basic
visual function.
Flexible
All of the test and stimulus parameters are configurable, providing
the investigator with a comprehensive set of options to suit different
applications.

A Wizard helps define every aspect of the test, including
calibration of the display, selection of the stimulus type and
its parameters, and the design of the test protocol.
Credible
Tried and tested psychophysical procedures are used to vary the
contrast of the stimulus automatically during the test. All of the test
method’s internal parameters are available for inspection during
the test and are displayed on a trial by trial basis. They can also be
saved with the test results for later review.

Results
The results are presented on a clear graph, which shows both the
data points and the fitted curve. To help compare results from multiple
trials and different subjects and to quickly determine changes over time,
data sets can be overlaid on the same graph. Graphs and data tables can
be printed to provide a hard copy of the results. The data points can
also be exported to a file for further statistical analysis in third-party
software.
Test protocols |
- Quest
- Zest
- Linear and logarithmic ascending and descending staircase
|
Alternate
forced choice tests |
- Location (2 or 4 way)
- Temporal (2 way)
|
Protocols |
- Can be stored, and locked to avoid accidental changes
|
Temporal envelope |
- Square wave
- Raised cosine
|
Subject feedback |
- Via infra-red response box
|
Simple subject
records |
|
Tabular results |
- Displayed throughout the execution of a test
|
Graphical
results |
- Spatial frequency vs contrast sensitivity
|
Export results |
- Directly to Excel
- In ASCII format
|
Reload results |
- Overlay multiple individuals
- Group fitting
|
Print results |
- Graphs, tables, test notes etc. can be printed
|
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