Abstract

Assessing the location of visual disturbance in a patient suffering from vision loss is crucial in determining patient management. This task is often made difficult by the presence of media opacities which may reduce visual quality in combination with any retinal or neural dysfunction. A number of tests, of differing complexity, may be employed to differentiate between these two causes of vision loss. A recent addition to this test battery is the measurement of vernier acuity thresholds. These belong to the class of "hyperacuities" in that they are of a magnitude far smaller than conventional resolution acuities and appear to be unlimited by retinal receptor spacing or receptive field size. Their value lies in the fact that they demonstrate resistance to optical image degradation such as that produced by cataract, yet they are affected by any retinal or neural dysfunction.

© 1987 Optical Society of America