Certified Ophthalmic Medical Technologist (COMT) Practice Exam

During the Worth 4-dot test, the presence of five lights indicates which condition?

1. Normal binocular vision

2. Suppression in one eye

3. Diplopia

4. Unilateral strabismus

The correct answer is: Diplopia

In the Worth 4-dot test, the presence of five lights indicates diplopia, which is the perception of two images of a single object. This situation occurs when the eyes are not aligned correctly, leading to the brain receiving conflicting visual signals from each eye. In this test, if a patient reports seeing five lights instead of the expected four, it suggests that their visual system is processing two separate images, which is indicative of diplopia. In normal binocular vision, the patient would typically see four lights, confirming that both eyes are working together and aligned properly. In cases of suppression, one eye's visual input is ignored, which would not lead to the perception of five lights. Unilateral strabismus, where one eye deviates from the normal focus, might not always result in diplopia, especially if one eye is suppressed. Therefore, the observation of five lights during the Worth 4-dot test specifically points to the condition of diplopia, validating the result and the importance of alignment and cooperation between the eyes.