Optical microscope
Microscope that uses visible light
The optical microscope, also referred to as a light microscope, is a type of microscope that commonly uses visible light and a system of lenses to generate magnified images of small objects. Optical microscopes are the oldest type of microscope, with the present compound form first appearing in the 17th century. Basic optical microscopes can be very simple, although many complex designs aim to improve resolution and sample contrast.
From Wikipedia, under CC BY-SA. More on occurri.