The Frisby Screening Stereotest is provides a single 6mm plate without studs in a easily portable special presentation box. This box facilitates easy presentations to children from about 6 months of age. For such young children ‘preferential looking responses’ at the target are particularly useful for establishing a positive result, that is, – stereo vision present.
The ‘target’ that the patient has to detect is printed on one side of each plate. This target is a cluster of randomly arranged arrowheads of differing sizes. See adjacent illustration.
Two squares are presented; one of which has a circle-in-depth.
Plate is held still and patient head movements avoided, if necessary by holding the head, with carer’s permission.
Plate is presented perpendicularly to the visual axes at a distance of 20-40cms.
The Frisby Stereotest Screening is particularly useful where language barriers can create difficulties in communication. The test is just shown to the subject by opening the presentation box, and a spontaneous pointing or looking response can be sufficient to establish that stereopsis is present.
The Frisby Screening Stereo Test is presented in good faith as a guide in assessing stereopsis. The diagnosis and any resulting action are the sole responsibility of the practitioner.
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