What are the two primary functions of a radioscope?

The primary functions of a radioscope focus on the specific requirements of contact lens fitting and assessment. The correct option highlights the significance of measuring sagittal depth and inspecting the posterior curve of the lens.

Sagittal depth is a crucial measurement in determining how a contact lens will align with the curvature of the cornea. By measuring this depth, practitioners can ensure that the lens fits appropriately on the eye, allowing for comfort and optimal visual acuity. The posterior curve of the lens is likewise vital, as it directly impacts how the lens conforms to the eye's surface. Inspecting this curvature helps in evaluating the lens's performance and ensuring it creates a proper relationship with the cornea.

The other options do not fully encapsulate the key functions of a radioscope. While analyzing curvature and measuring thickness (option C) might seem relevant, these functions are not as critical as understanding the relationships of the lens's shape to the eye, specifically regarding sagittal depth and posterior curvature. Inspecting lens shape and measuring power (option D) also addresses important aspects but again does not prioritize the necessary fit and conformance that sagittal depth and posterior curve measurements provide. Thus, the correct answer emphasizes the essential components for achieving a proper fit in contact lens fitting practices.