Eyepieces are optical components used in devices like telescopes and microscopes to magnify images for the viewer. They are typically located at the end of the instrument where the user looks through. Eyepieces come in various designs and magnification levels, allowing users to choose the best option for their specific needs. The design of an eyepiece can affect the quality of the image seen. Common types include Huygens, Kellner, and Plössl eyepieces, each offering different fields of view and levels of distortion. Choosing the right eyepiece can enhance the overall viewing experience and improve clarity and detail.