Answer:
I believe you are asking about the objective lens or eyepiece.
Step-by-step explanation:
Objective lenses are used to magnify objects enough for you to see them in great detail
Eyepiece/Ocular is what you look through at the top of the microscope.
A tube connects the eyepiece lens to objective lenses, which enhance the magnification power of the eyepiece lens. Both the eyepiece and the objective lens contribute to the magnification of the object.
The eyepiece lens usually magnifies 10x, and a typical objective lens magnifies 40x.