The slit lamp is a device which focuses a high intensity light beam (that can be focused as a slit) at the structures of the eye while the examiner looks through a magnifying scope. Eyedrops which numb the eyes and dilate the pupils will often be used prior to examination. The exam is not at all uncomfortable, just time consuming.
diagnoses such as foreign body (to conjunctiva, cornea or sclera), iritis, herpes keratoconjunctivitis, cornmeal ulcer, cataracts, glaucoma and corneal abrasions may be made using this exam. Some foreign bodies can even be removed using the enhanced image amplification of the slit lamp.