Certified Ophthalmic Medical Technologist (COMT) Practice Exam

In indirect ophthalmoscopy, what effect does the instrument have on the appearance of the fundus image?

1. It appears brighter

2. It appears inverted and reversed

3. It appears clearer

4. It appears smaller

The correct answer is: It appears inverted and reversed

In indirect ophthalmoscopy, the appearance of the fundus image is fundamentally affected by how the instrument manipulates the light and optics involved in viewing the retina. The correct answer highlights that the image appears inverted and reversed due to the design of the system consisting of a condensing lens and a viewing lens. When light from the fundus passes through the condensing lens, it creates an image that is effectively flipped both horizontally and vertically. This inversion is a result of the optics where light rays cross one another as they are refracted through the lenses. As a result, what is observed in the fundus is not in the same orientation as its actual anatomical alignment. The other choices describe potential characteristics of the fundus image that do not accurately reflect the optical effects of indirect ophthalmoscopy. For example, while the image may appear brighter due to the additional light collection, the primary defining feature during indirect ophthalmoscopy is its inversion and reversal. Clarity may vary based on other factors but is not inherently a result of the optical system itself. Size perception can also be affected by the optical properties of the lenses used, but inversion and reversal are the guaranteed effects observed during the process.