Amblyopia and Eccentric Fixation
Amblyopia Definition Hippocrates in 400 BCE described amblyopia as ‘when the doctor and patient see nothing’ ( Day, 1997 ). Lyle and Wybar (1967) defined amblyopia as ‘a condition of…
OPHTHALMOLOGY
Eye Exercises for Heterophoria
The preceding chapters on various heterophoric anomalies have described the general outlines for the management of these conditions. This chapter gives details of particular exercises which may be fitted into…
Overview of Sensory Changes in Strabismus
Binocular Sensory Changes in Strabismus Diplopia and Confusion Diplopia occurs when a patient sees two images of one object. Fig. 12.1 A represents an adult with recent onset left esotropia….
Anisometropia and Aniseikonia
Binocular vision can be disturbed by large differences in the refractive error between the two eyes: anisometropia . When this is left uncorrected, central suppression areas can develop in the…
Evaluation of Heterophoria
Introduction A heterophoria only requires treatment if it is causing symptoms or impaired performance, if the binocular status is likely to deteriorate if it is not treated, or if the…
Hyperphoria and Cyclophoria
Hyperphoria is a potential deviation of one eye upwards which becomes an actual deviation when the two eyes are dissociated, and which recovers when the dissociating factors are removed. In…
Exophoric Conditions
Although it has been shown that divergence is actively stimulated ( Breinin, 1957 ), exophoria appears to be a much more passive condition than esophoria. There are several potential explanations…
Esophoric Conditions
Most esophoria is ‘accommodative’, in that it largely results from excessive accommodation due to uncorrected hypermetropia or prolonged close work. As a result of the accommodation/convergence linkage, the overactive accommodation…
Management of Heterophoria: Basic Principles
Before dealing with the individual heterophoric conditions in the next three chapters, this chapter outlines the basic principles of management. There are two reasons to treat a heterophoria: to alleviate…
Binocular Instability
A heterophoria is compensated when the vergence system can adequately overcome the heterophoria. Yet there are subjects with a negligible heterophoria and whose opposing fusional reserves meet the conventional criteria…
