Slit lamp

This is a biomicroscope with an optical system used to exam the anterior segment and posterior segment of the eye. With its help various cases can be diagnosed such as faulty position, movement, shape or appearance of the eyelids, lacrimal system and tear film, conjunctival algae (a highly sensitive indicator of dry eye syndrome), etc.

Different colour filters may be placed in front of the light source. The most important is a cobalt blue filter, intended to observe the colouration of various ocular tissues by the use of fluorescein – see fluorescein test.