Which type of illumination is primarily used for examining the globe and extraocular structures?

Diffuse illumination is primarily used for examining the globe and extraocular structures due to its ability to provide a broad, even light source that reduces glare and enhances visibility of the deep structures of the eye. This technique involves the use of a wide beam of light that illuminates a large area, allowing for a comprehensive view of the ocular surface as well as adjacent structures. It is particularly beneficial for assessing the health of the cornea, conjuctiva, and the surrounding tissues without overwhelming them with harsh light.

In contrast, direct illumination typically focuses on a small area and can create shadows that might obscure crucial details. Indirect illumination is specifically useful for examining deeper structures but may not provide the full view needed for surface evaluation. Transillumination is often used to assess the presence of lesions or abnormalities within the structures by passing light through them, making it less suitable for a general examination of the globe and surrounding tissues. Thus, diffuse illumination is the technique that provides the most thorough evaluation for these anatomical areas.