Raycasting without a direction

Is there a way to raycast without a direction to see what colliders are directly around an object? I'm trying to create a dynamic lighting script, so I need to be able to check which objects the light can "see".

My other idea was to use a SphereCast with collision so that I could check which objects were adjacent to the light, and that the light could see. Are either of these options possible?

Thanks, Chad.