The purpose of this communication is to correct what I believe to be misconceptions concerning certain visual phenomena associated with strabismus by pointing to significant facts hitherto overlooked or disregarded. These misconceptions are so prevalent that their correction is of considerable importance. Of the misconceptions in question, probably the most misleading relate to anomalous projection.
Before this remarkable phenomenon can be intelligibly discussed, it is essential that a precise definition of corresponding retinal points be given. Many such definitions have been attempted, some of which are evidently inaccurate, while others are inadequate or ambiguous.1 The following definition, which, so far as I know, has never previously been definitely expressed, has certain advantages, particularly for the purpose of discriminating between normal and anomalous projection. With the head stationary, fix with one eye (for the present assumed to be the right) the center of any suitable object, A, as in