The effectiveness of a retinoscope beam as an accommodative stimulus.

Two experiments with adult subjects and one with infant subjects showed that the beam of a retinoscope, when viewed monocularly in a dark surround, does not stimulate accommodation. In this situation, the eye assumes an intermediate focus that is correlated with the individual's intermediate dark focus or resting state of accommodation. These results provide further evidence that near retinoscopy is a useful method of refraction which controls accommodation by minimizing effective stimulation. The technique is particularly valuable for refracting infants or young children who would otherwise require cycloplegia, and it may be an effective clinical method for the correction of night myopia and related anomalies in adults.