An eyepiece is a lens or a series of lenses used in optical instruments like telescopes and microscopes to magnify the image produced by the objective lens. It is the part of the instrument that the user looks through, allowing for detailed observation of distant or tiny objects. Eyepieces come in various designs and magnification levels, which can affect the clarity and field of view. In addition to magnification, eyepieces can also influence the comfort of viewing. Some eyepieces are designed with features like adjustable eye relief, making them suitable for users who wear glasses. The choice of eyepiece can significantly enhance the overall experience of using optical devices.