There are many. The general term would be optical instruments
To view things from far away is called a binocular
instrument used to view the eye
periscope
A microscope.
A telescope is used to view objects that are far away by gathering and focusing light to magnify distant objects. Telescopes can be used for astronomical observations as well as to view distant terrestrial objects such as mountains or wildlife.
Retinascope
our naked eyes...
A telescope is used to view things far away.
The instrument used is a microscope. This has a number of lens, for instance, you can choose to magnify the cell or whatever it is x4/x10/x40. Hope this helps :)
periscope
The medical term for an instrument used to view small objects is "microscope." It is commonly used in various medical fields for examining cells, tissues, or microorganisms at a magnified level.
An optical telescope is the simplest instrument to view the heavens.