Final answer:
A wide-angle lens is the type of special lens that provides a broader field of view when observing a specimen through a microscope.
Step-by-step explanation:
The special lens that offers a broader field of view (FOV) when viewing a specimen under a microscope is known as a wide-angle lens. Microscopes utilize components such as the eyepiece and objective lenses to magnify small objects, where each contributes to the final magnification. The numerical aperture (NA) of an objective lens is critical for determining its light-gathering ability and is calculated using the angle of acceptance and the refractive index of the medium. High NA lenses have improved resolution and light-gathering capacity, which can be further enhanced using immersion techniques. A broader FOV is crucial for observing more of the specimen at once without sacrificing image quality.