[Solved] The best safeguard for a robot is a barrier around the perimeter of its work envelope. Optical Microscopes: Instruments that use visible light and a system of lenses to magnify small objects, allowing for the observation of details not visible to the naked eye. Physicians' Office Laboratories: Labs located within a physician's office where various tests are performed on clinical specimens to obtain information about the health of a patient. Objectives: The set of magnifying lenses contained in the nosepiece of a compound microscope. Optical Microscope: An instrument that uses visible light and a system of lenses to magnify images of small subjects.