Walsh & Hoyt: Refraction and Visual Acuity

A thorough refraction is an essential part of all clinical neuro-ophthalmologic examinations. Identification of a previously undetermined refractive error, corneal pathology, or a subtle lens problem can prevent initiation of an expensive and time-consuming evaluation. It is essential to have the best refraction possible when measuring visual acuity to distinguish whether visual acuity loss is caused by optical factors or damage to neural elements in the visual system. Refractive problems can not only cause loss of visual acuity but may also produce symptoms such as monocular diplopia.