Certified Ophthalmic Assistant Practice Exam

Which tool consists of a series of red cylinders used to assess phobia?

1. Maddox rod

2. Snellen chart

3. Cover test

4. Visual field analyzer

The correct answer is: Maddox rod

The tool that consists of a series of red cylinders used to assess phoria is the Maddox rod. This device helps in evaluating the alignment of the eyes when focusing on a target. When using the Maddox rod, a red light is viewed through the rod, creating a red line that helps detect any deviation in eye alignment. This is crucial for understanding if a patient has a phoria, which is a tendency for the eyes to deviate when binocular vision is disrupted. Testing with the Maddox rod specifically targets conditions where one eye may drift while the individual is focused on an object, revealing latent strabismus that might not be apparent without binocular visual stimulus. The results guide further diagnosis and treatment of binocular vision issues. The Snellen chart is utilized for visual acuity testing, the cover test assesses eye alignment, and the visual field analyzer evaluates the peripheral vision, all of which serve different purposes within ophthalmic assessments but do not involve the specific measurement of phoric conditions like the Maddox rod does.