4-Dot Test

The purpose of the 4-Dot Fusion test is to assess a patient’s degree of binocular vision.


What is the test? The test consists of four dots, a red dot positioned at the top, a green dot on the horizontal left and right and a white dot at the bottom. When using red/green glasses, the colors should remain the same except for the bottom white color that will appear as white or flickering white with green or red. If this is what the patient identifies then they have normal binocular single vision.

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What is the purpose of the test? To assess a patient’s degree of binocular vision, that is when assessing the function of the eyes to work in coordination. More specifically, it tests for fusion, suppression, and anomalous retinal correspondence (ARC).


Why is this important? The test is among the more straightforward techniques for testing fusion, anomalous retinal correspondence and suppression.

The RightEye test is similar to that of The Worth Four Light Test (Worth's Four Dot test, W4LT). The 4-Dot fusion test has been evaluated for its reliability, that is the consistency of results, which according to gold standards (the Cronbach Alpha; Fleiss, 1986) has passed with a rating of “excellent” (CA = .929). The Four Dot Fusion Test has also been examined for validity. When comparing the RightEye Four Dot Fusion (digital) Test to the clinical gold standard, Worth Four Dot Fusion test, results revealed no significant differences (p > 0.05). Therefore, these results indicate that the two tests are equivalent in their output and the Four Dot Fusion test can be used in replacement of the Worth Four Dot test.



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