The document discusses optical microscopes, which use visible light and a system of lenses to magnify small samples. Some key points:
- The first compound microscope was created in the late 16th century by Dutch spectacle makers Zacharias Jansen and his father Hans.
- There are different types of viewing heads including monocular, binocular, and trinocular.
- Magnification is calculated by multiplying the magnification of the eyepiece and objective lens. Maximum normal magnifications are 10x for eyepieces and 100x for objectives.
- Optical microscopes have applications in fields like microelectronics, biotechnology, medical diagnosis, and industrial measurement and quality control.