What are the functions of the tube?

The tube is the main part of the microscope. This is due to the fact that it is in the tube that the lenses are installed, which allow you to see the enlarged image. The tube can be adjusted. Some modern microscopes have a more complex structure and the tube has not one eyepiece, but two. This makes it much more convenient and better to study the drugs. The tube was still in the first microscope, but it was Robert Hooke who was able to improve the microscope. After improving the design, it became possible to study cells. So Hooke studied the first living cell and described it.