slit-lamp(redirected from Volk lens)
slit-lampA low-power, binocular microscope with an intense light source, used to examine the internal structures of the front part of the eye and, by means of special eye contact lenses, the VITREOUS BODY and the RETINA.
Instrument producing a bright focal source of light with a slit of variable width and height. It may be used to examine the tissues of the anterior segment of the eye in conjunction with a microscope (usually binocular) of variable magnification. To examine the internal structures of the eye including the retina an auxiliary lens is required. Many such lenses exist, some which do not make contact with the eye (e.g. Hruby lens, Volk lens) and others which come in contact with the eye, usually like a scleral type of lens (e.g. Goldmann lens, Thorpe four mirror fundus lens, Wilson three mirror fundus lens). A slit-lamp is essential in contact lens practice. This instrument is also commonly called a biomicroscope (Fig. S9). See fundus biomicroscopy; gonioscope; illumination; Shaffer and Schwartz van Herick method; Smith's method; slit-lamp microscope; endothelial polymegethism.