This paper is, at least in part, deduced from a review of the records of examination of 1000 eyes of my own patients, in private practice, in which artificial cycloplegia has been purposely produced for the sake of optometric examination. The case records of 5257 of my first private patients have been required in order to have the desired data concerning 1000 eyes. Of the cases in which cycloplegia had been produced for the purpose of optometric examination, 19.7 per cent. were unfit for use in the preparation of this paper, because of the incompleteness of my novitiate records, which incompleteness prevented the desired comparison of the seeming static refraction, before cycloplegia, and that found during cycloplegia. The number of eyes, the records of whose examination are trustworthy—1000— was chosen partly because of the facility of computing percentages from that number and partly because time for reviewing a greater number