Using a +20D lens for non-contact slit lamp biomicroscopy of ocular fundus
Noncontact slit lamp examination of the ocular fundus has been classically done using high power convex lenses like +90D, +78D, and +60D. A real and inverted image of the fundus is formed in between the high power convex lens and the slit lamp. The +20D lens is commonly used for binocular indirect ophthalmoscopy. The authors use this +20D lens for slit lamp biomicroscopy examination of the fundus.