ABSTRACT
Visual acuity is usually not particularly impaired after unilateral postchiasmatic brain injury except in cases where the optic tract is involved. In patients with impaired spatial contrast vision, visual acuity may be unaffected if tested using high-contrast single optotypes. Patients with acquired posterior brain injury sometimes complain of “blurred” or “foggy” vision in the presence of normal visual acuity, accommodation, and convergence. The measurement of spatial contrast sensitivity has been found to be useful to understand better visual impairment in tasks involving a high resolution capacity of the visual system, as for example in reading or fine form discrimination. The visual environment appeared “foggy” and patients reported being considerably impaired in many of their daily activities. Light and dark adaptation can be affected after uni- as well as bilateral postchiasmatic brain injury. Patients with impaired light adaptation often complain of a strong sensation of being “blinded” under normal daylight or artificial illumination conditions.
