When evaluating the posterior segment the direct ophthalmoscope is used to assess the vitreous, optic disc and retina, and to identify abnormalities or the need for further investigation. Abnormalities picked up in the posterior segment can be more thoroughly examined through dilated pupils using slit-lamp or head mounted indirect ophthalmoscopy.
Slit-lamp examination of the lids, lashes, conjunctiva, sclera and cornea is important during contact lens fitting and aftercare and for those patients when symptoms or signs suggest the problem may lie with these ocular structures. Diffuse illumination refers to a wide beam that is directed obli...