Endoscopy is a method of observation that allows direct viewing of certain internal structures of the eye which cannot be easily visualized through conventional slit lamp/microscope arrangements. An endoscopic system can also be helpful when a transparent structure of the eye becomes turbid, e.g., a hazy cornea. Over the past years substantial efforts have been oriented to miniaturize endoscopes for use in ophthalmology. Ophthalmic endoscopes have been presented on the basis either of coherently ordered fiber bundles or of optical lenses such as the gradient-index ones (GRIN). Endoscopes that provide a basic visualization function can also be fitted with one or more ancillary channels that may provide additional features such as aspiration/injection or laser treatment.