{'fraction_non_alphanumeric': 0.024390243902439025, 'fraction_numerical': 0.008130081300813009, 'mean_word_length': 5.158333333333333, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
THE EFFECT OF CONTACT LENS THICKNESS AND CORNEAL TORICITY ON FLEXURE AND RESIDUAL ASTIGMATISM*

ABSTRACT Contact lens flexure and the associated change in residual astigmatism were measured with lenses of various center thicknesses on corneas of various toricities. On spherical and nearspherical corneas, none of the lenses flexed significantly or altered the residual astigmatism. On toric corneas, thick lenses (t > 0.13 mm) did not flex significantly; however, thin lenses (t < 0.13 mm) did flex significantly, and did alter residual astigmatism in a predictable manner. The findings of this study can be used to alter the amount of residual astigmatism of toric corneas by making appropriate changes in contact lens center thickness.