Microscopes have more than two lenses. They contain two main sets of lenses: the objective lens and the eyepiece or ocular. Objective lenses generally contain multiple elements, and there can also be additional lenses within the microscope itself, such as a condenser lens, field lens, and more.

Each of these lenses plays a crucial role in magnifying and focusing the image of a specimen:

1. Objective Lens:

- The objective lens is the lens located at the bottom of the microscope, closest to the specimen.

- It is responsible for creating the initial magnified image of the specimen.

- Different objective lenses have different focal lengths and magnifications.

- Objectives are typically interchangeable and come with various power levels.

2. Eyepiece or Ocular:

- The eyepiece is located at the top of the microscope, where you look through it to observe the specimen.

- Its primary function is to magnify the image formed by the objective lens, allowing you to view it comfortably and with increased detail.

The objective and eyepiece lenses work together to provide the total magnification of a microscope:

Total Magnification = Objective Lens Magnification X Eyepiece Magnification

For example, if the objective lens has a magnification of 10X and the eyepiece magnification is 10X, the total magnification of the microscope would be 100X.

Additional lenses, such as the condenser lens, help focus light onto the specimen, while field lenses and relay lenses are used to further manipulate and enhance the image.