Predicting the axis and power of astigmatism using a retinoscopic method

摘要

The different shadow movements of retinoscopy using trial cylindrical lenses at different obliquities from the true axis of astigmatism are analysed. A method of predicting the true axis and the power of low to moderate astigmatism is proposed, based on induced changes in the reflex movement with the addition of a single, low‐powered cylindrical trial lens. Explanations for these changes in reflex position are give