Portable microscopes are mainly an extension of the series of digital microscopes and video microscopes developed in recent years. Unlike traditional optical amplification, hand-held microscopes are all digital amplification devices that generally seek portability, compactness, refinement, and portability; Some hand-held microscopes have their own screens that can be independently imaged from a computer host, making them easy to operate. They can also integrate some digital functions, such as support for photographing, video recording, or image comparison, measurement, and other functions.

Generally, it consists of an optical part, a lighting part, and a mechanical part. Undoubtedly, the optical part is the most critical, consisting of an eyepiece and an objective lens. As early as 1590, eyewear manufacturers in the Netherlands and Italy had built magnifying instruments similar to microscopes. There are many types of optical microscopes, mainly including bright field microscopes (ordinary optical microscopes), dark field microscopes, fluorescence microscopes, phase contrast microscopes, laser scanning confocal microscopes, polarizing microscopes, differential interference difference microscopes, and inverted microscopes.