90D Description Patented double aspheric glass optics provide enhanced imaging, Original 90D lens started the slit lamp fundus examination revolution Small diameter ring is ideal for dynamic fundoscopy Outstanding general diagnostic lens, even through small pupils 78D Description Patented double aspheric glass optics provide enhanced imaging High magnification provides excellent views of the optic disc and macula Perfectly corrected for field curvature, astigmatism, aberrations and coma 20D Description 20D Lens provides an extended working distance from cornea. The 20D Aspheric slit lamp lens for non-contact fundus examinations. Specifically packaged in a hard-case ensuring safe reach. High quality lens with a great value for money. 20D Slit Lamp Lens offers an ideal combination of field and magnification Sterilizable, Perfect equilibrium of magnification and field of view