APA Dictionary of Psychology

the sensation resulting from impairment of the ability to perceive form in the central field region, which is typically associated with poor visual acuity and reduced spatial contrast sensitivity. Visual blurring can occur as a result of retinal disease (e.g., macular degeneration, diabetic retinopathy) or damage to the optic nerve (e.g., associated with multiple sclerosis) or visual cortex; it has also been reported as a side effect of anticholinergic drugs and as a consequence of accommodative spasm. Patients experience difficulties with reading and face perception (especially in black-and-white photographs).