An endoscope is used to view the esophagus and stomach.
a diagnostic procedure that is performed to view the esophagus, stomach, and duodenum (part of the small intestine).
The special instrument used to view the esophagus, stomach, and duodenum during an esophagogastroduodenoscopy (EGD) is called an endoscope. This flexible, tube-like instrument is equipped with a light and camera, allowing physicians to visualize and assess the mucosal lining of these structures for abnormalities or diseases. Additionally, the endoscope may be used to perform minor procedures, such as biopsies or the removal of polyps.
instrument used to view the eye
A microscope.
To view things from far away is called a binocular
Retinascope
our naked eyes...
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.
There are many. The general term would be optical instruments
A microscope is used to view smaller objects at a magnified scale, allowing for detailed observation of structures that are not visible to the naked eye.