Which type of illumination uses reflected light to observe a portion of the eye?

Indirect illumination is the correct choice because it involves using a beam of light that is reflected off a surface to illuminate a specific area of the eye. This technique allows the practitioner to observe structures that may be difficult to see with direct light and provides a clearer view of the eye's anatomy by utilizing the light that bounces off different surfaces.

In practice, indirect illumination typically involves using a light source at an angle, which helps to create a shadow effect that enhances the visibility of the structures within the eye. This method is particularly useful when examining the retina or other inner ocular features because it minimizes glare and maximizes contrast, making it easier to detect abnormalities.

Understanding this technique and its application is essential for eye care professionals, as it enables them to provide accurate assessments of a patient's eye health.