Final answer:
The area visible when looking through a microscope's oculars is known as the field of view. It is the specific section of the specimen that can be seen at any given magnification, which is limited by the eyepiece and objective lens.
Step-by-step explanation:
The area you see when looking into the microscope through the oculars is called the field of view. The field of view is the visible area of the specimen or sample when looking through the microscope's eyepiece. This area is limited by the specifications of the eyepiece and objective lens. While using the microscope, the objective can be manipulated in two dimensions above the stage, allowing different regions of the specimen to be viewed. For scanning microscopy, electronic scanning is used to collect images from various points, which a computer then combines to create an image of a larger sample area at the chosen magnification.
The specimen is placed on a glass slide and secured on the stage, which has x-y mechanical stage knobs to move the slide without raising or lowering the stage. Focusing is done using both the coarse and fine focusing knobs, with the objective lenses having magnifications typically ranging from 5x to 100x. The final image is magnified by the objective lens first and then further enlarged by the eyepiece for comfortable viewing.