Visual field constriction with relatively preserved central vision: an unusual case of early-onset retinal dystrophy.

The authors report a case of visual field constriction with relatively preserved central visual acuity caused by early-onset retinal dystrophy in a 17-year-old girl. Although uncommon, such a phenomenon associated with Leber's congenital amaurosis, retinitis pigmentosa, and related diseases should be considered in early-onset visual field constriction.

The Pulfrich effect in the clinic.

First described in 1922 by Carl Pulfrich, the Pulfrich effect is a stereo-illusion thought to be caused by an inter-ocular signal latency difference stimulating neurons jointly tuned to disparity and motion. Clinically, this can be a spontaneous manifestation due to various ocular and central visual pathway pathologies, and cause symptoms independent of a range of routine visual parameters which may seem bizarre to both the patient and the clinician. Eliciting such symptoms of difficulties with motion and depth perception in a clinical history should direct the clinician to the possibility of the presence of the spontaneous Pulfrich effect, and to proceed to test for it.