VISION- ITS DEVELOPMENT IN INFANT AND CHILD by ARNOLD GESELL, M. D. FRANCES L. ILG., M. D. GLENNA E. BULLIS. Assisted by VIVIENNE ILG, O. D. and G. N. GETMAN, O. D. PAUL B. HOEBER, INC. MEDICAL BOOK DEPARTMENT OF HARPER i-BROTHERS. PREFACE: The background, scope, and genesis of the present volume are outlined in an introductory chapter which follows. There is not much more which needs to be said by way of preface. The investigations of the Yale Clinic of Child Development since its founding in 1911 have been mainly concerned with the growth aspects of early human behavior. All told, the behavior characteristics of 34 age levels have been charted, encompassing the first ten years of life. An intensive longitudinal study of a group of five infants in 1927 established methods for a systematic normative survey. These methods included developmental examinations and inventories at lunar month intervals during the first year of life. Concurrent cinema records were analyzed to define significant behavior patterns and growth trends. Special attention was given to the ontogenetic patterning of posture, locomotion, prehension, and manipulation. Cinemanalysis, both of normative and experimental data, demonstrated that the eyes play an important role in the ontogenesis of the total action system of the total child. The nature and the dynamics of that role constitute the subject matter of the present study. The adult human eye has been likened to a camera. This analogy has had some truth and much tradition in its favor. But it has tended to obscure the developmental factors which determine the structure and the organization of the visual functions during infancy and child hood. The development of vision in the individual child is an extremely complex and protracted process for the very good reason that it took countless ages of evolution to bring human vision to its present pre-eminence. Our culture is becoming increasingly eye minded with the advancing perfection and implementation of the organ of sight. What is that organ It is more than a dioptric lens and a retinal film. It embraces enormous areas of the cerebrum it is deeply involved in the autonomic nervous system it is identified reflexively and directively with the skeletal musculature from head and hand to foot. Vision is so perva sively bound up with the past and present performances of the organism that it must be interpreted in terms of a total, unitary, integrated action system. The nature of the integration, in turn, can be understood only through an appreciation of the orderly stages and relativities of development whereby the integration itself is progressively at tained. The authors have attempted to achieve a closer acquaintance with the interrelations of the visual system per se and the total action system of the child. This finally entailed the use of the retinoscope and of analytic optornetry at early age levels where these technical procedures ordinarily are not applied. The examinations of the visual functions and of visual skills were really conducted as behavior tests, not only to determine the refractive status of the eyes, but also to determine the reactions of the child as an organism to specific and total test situations. The objective findings have been correlated with the cumulative evi dence furnished by the developmental examinations, numerous inter views, and naturalistic observations of the children at home and in a guidance nursery. Although the conclusions of our study are preliminary in character, we may hope that they will contribute to a better understanding of the child in terms of vision and a better understanding of vision in terms of the child. The two should not be sundered. With increased knowledge it is possible that the visual behavior of the individual child will become an acute index for the appraisal of fundamental constitutional traits.