[Solved] Find the domain of the function. Eyepieces: Optical lenses located at the viewing end of a telescope, microscope, or other optical instruments, through which the user looks. Magnifying Lens: An optical instrument designed to enlarge the appearance of objects or text, making details more visible to the naked eye. Microscope: A device used to view objects that are too small to be seen by the naked eye, by magnifying them. Specimen: A sample taken from a body, such as tissue, blood, or urine, used for analysis or diagnosis.