A reconsideration of amblyopia screening and stereopsis.

The need for routine amblyopia screening of all children, making such screening "as important a part of medical care as immuni­ zations," is all but self-evident. Although, as Lippman points out, many of the traditional incidence statistics need interpretation to be meaningful, most recent large-scale screening efforts of children indicate an amblyopia in­ cidence of 1 to 3 % in the general popula­ tion.' The corrected statistics of a recent largescale screening study of preschoolers in Israel suggest even higher amblyopia incidence fig­ ures may be correct, however. Oliver and Nawratzki report an incidence ranging be­ tween 0.4 and 2.1% in the \y2to 6-year-old age groups they screened. These figures were based on the number of amblyopes detected out of the total number of children included in the study. The number of children who cooperated with the testing was much smaller than this total, however, and seems a more valid base for the incidence statistics. When the children who cooperated are thus taken as the denominator of the proportion, the prevalence figures work out to the following (i.e., the corrected form of Table l 8 ) : Group A (V/2 to 2 years old), 8% ; Group B (2 to 3 years old), 5 % ; Group C (3 to 4 years old), 2% ; Group D (4 to 5 years old), 5.6% ; and Group E (5 to 6 years old), 12%.