I think it's the microscope lens or the objective lens.
Hope this helps!
zoom
a diaphrgam is part of a microscope that controls brightness or light on the object you are looking at.
The 'object lens' in a compound microscope is closest to the object being examined.
The 'object lens' in a compound microscope is closest to the object being examined.
The objective lens
The part of the microscope that you look into is called the eyepiece.
Supports upper part of the microscope
The objective lens
the arm
The 'object lens' in a compound microscope is closest to the object being examined.
at the ARM of a microscope...
it is part of a microscope.