Stereo microscopes provide a 3-dimensional, non-inverted view that make them indispensable in tasks such as dissections and in-vitro fertilization. While this section falls within the "Biological" part of this site, the applications for stereo microscopes are in no way limited only to biology.
Greenough-design stereos are the most common type and the least expensive. The design consists of two identical optical paths each containing a separate eyepiece and objective arranged in a slightly converging alignment within a single housing. Easy to use and maintain, these stereos can be found practically everywhere!
Common-Main-Objective (CMO) stereo microscopes typically offer higher quality optics than their Greenough counterparts. Modular by design, a viewing head mounts onto a main optical body that contains the zoom mechanism. Both optical paths (left and right eyes) then share an objective that screws on to the bottom of the main optical body. Most CMO stereos have wider zoom ranges than Greenough-design scopes and are used in more advanced and research functions.