@entity227 in XXXX and @entity1781 .

@entity227 @entity17 @entity63 @entity1833 @entity1781 @entity74 @entity5995 @entity1020
@entity227 seen with @entity5995 and @entity1781 may overlap with those resulting from @entity74 . A few disorders typically present with distinctive perceptions, but the majority have less specific symptoms. Features include whether or not the visual phenomena are negative or positive, monocular or binocular, and the location and form of any deficits. Among negative phenomena, transient @entity227 usually is the result of @entity63 , but particular precipitants may suggest @entity17 . The pattern and location of @entity227 may help localize disorders to the level of the macula, papillomacular or other inner retina nerve fiber bundles, optic nerve, or chiasm. Altered brightness perception may point to optic nerve or photoreceptor disease. Decreased acuity is among the most common and least specific symptoms, but association with other symptoms may help to narrow the differential diagnosis. Dyschromatopsia points to either a photoreceptor or optic nerve pathologic condition (Table 7). Among positive phenomena, @entity1833 resulting from @entity227 typically are unformed, although deafferentation of retrochiasmal pathways may produce formed @entity1833 . The common "floaters" frequently are benign, but occasionally herald more concerning disorders. Various types of photopsias commonly occur with vitreal @entity74 . @entity1020 typically leads to distortions of the central visual field, and other @entity74 lead to a host of characteristic distortions of color, form, or brightness. Careful attention to the ophthalmologic examination, visual fields, and subtle variance in symptomatology also help to distinguish among @entity74 .
