What is an erecting eyepiece?

An erecting eyepiece is a type of optical component used in telescopes and binoculars that corrects the orientation of the image, allowing the viewer to see it right-side-up and correctly oriented left-to-right. This is particularly useful in terrestrial observations, where an inverted image may be disorienting. Erecting eyepieces typically consist of multiple lenses arranged to achieve this correction while maintaining image clarity and brightness. They are commonly used in refractor telescopes and spotting scopes designed for land viewing.