Accommodation causes with-the-rule astigmatism in emmetropes.

PURPOSE

To measure the changes in astigmatism when bilateral emmetropes accommodate.

METHODS

Bilateral emmetropes accommodative responses were measured with an improved photorefractometer PR-1100, which measured binocular refraction in all meridians simultaneously as a fixation target was shown in natural space.

RESULTS

The accommodative responses in the vertical meridian are greater than those in the horizontal meridian. In the horizontal meridian, the accommodative responses are less than the accommodative stimulus.

CONCLUSIONS

When accommodating the majority of bilateral emmetropes show with-the-rule astigmatism and lag of accommodation in the horizontal meridian.