Complex sentence: In Hindu temples, their role is envisioned to symbolically radiate the light and splendor of the central icon in its sanctum, as an aperture for the deity to gaze out into the world.
Split into simpler sentences: In Hindu temples, their role is envisioned as symbolically radiating the light and splendor of the central icon in its sanctum. Alternatively, they are described as providing a window for the deity to gaze out into the world.