Abstract

After the publication of the research of Howland and Howland¹ several authors used eccentric photorefraction to measure refractive errors and accommodation (e.g. Kaakinen², Norcia et al.³, Bobier and Braddick⁴, Schaeffel et al.⁵, Angi and Cocchiglia⁶) or the development of myopia (Schaeffel and Howland⁷). But a set-up which can be used by untrained persons and allows automatic examinations of large numbers of subjects is not available in the market. In Europe several scientific working groups and the Italian company Fortune Optical found together to develop an automatic refractometer based on eccentric photorefraction which can be used for screening. In such a set-up it is not sufficient to reduce the image processing on measurements of the crescents’ width, because their inner borders are only unsharply defined, but rather is it necessary to take the total light distribution in the pupil into account.

© 1995 Optical Society of America