the optical system of a microscope is the objectives

The points on the optical axis OO' (see Figure 1) of a centered optical system that can be used to construct the image of an arbitrary point in space for objects in the paraxial region, which is the region around the axis of symmetry of the system where a point is represented by a point, a straight line by a straight line, and a plane by a plane.

"Optical" means related to light, often to visible light. So, a system that works with light.

I think that she invented 3 things such as 1). an optical inspection system 2). optical object recognition method and 3). nose removal in images

EOS is Electro-Optical System. It controls the optics of a lens through electronic system.