Certified Ophthalmic Assistant Practice Exam

Which of the following cannot be used for color vision testing?

1. Pseudoisochromatic plates

2. Hardy-Rand-Ritter plates

3. Nagal anomaloscope

4. Fly test

The correct answer is: Fly test

The Fly test is not typically used for color vision testing because it does not assess the ability to differentiate colors in the same way as the other methods listed. Instead, the Fly test is fundamentally a visual acuity test that might incorporate some elements of depth perception or motion detection, but it lacks the specific color differentiation that is essential for color vision assessment. In contrast, pseudoisochromatic plates, Hardy-Rand-Ritter plates, and Nagal anomaloscope are established tools for evaluating color vision. Pseudoisochromatic plates rely on color differences to distinguish between various colors and are designed to reveal color deficiency. Hardy-Rand-Ritter plates provide a similar function but use a different method that includes patterns appearing in various colors, facilitating the identification of specific color deficiencies. The Nagal anomaloscope is a more complex device that allows for the matching of colors and helps in diagnosing the type and degree of color vision deficiency, especially red-green color deficiencies.