Eyepiece

Eyepieces, also known as oculars, are usually considered a requirement for visual observation using a telescope. The eyepiece magnifies the image created by the primary objective (the main mirror or lens) to make it suitable for our eyes.

There are a number of different eyepiece designs, all with advantages and disadvantages unique to each design. Some eyepieces are not suitable to be used in some telescopes for all targets. When considering an eyepiece for use in visual observation, it is important to keep this in mind. This page lists the most common eyepieces used by amateur astronomers.

A wealth of practical information and example images can be found at the wikipedia article on eyepieces.