The slit lamp, or biomicroscope, is a tabletop microscope that uses an adjustable beam of light to provide concentrated illumination and magnification of various parts of the eye. The light beam may be adjusted both as to width of the slit of light and the height of the slit -- thus the term, "slit lamp." This microscope magnifies the structure of the eye some 6 to 40 times, and the eye doctor uses it to detect and evaluate any abnormalities in the structures of the eye.
Comprehensive eye examinations comprise an evaluation of the physiologic function and anatomic status of the eye, visual system and its related structures, and always include a slit lamp examination. Before a slit lamp examination, the eyes are sometimes dilated with special eye drops to enlarge the pupil size. This provides the doctor with a larger "window" to examine the inside structures of the eye.
