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Changes in astigmatism with accommodation
Author(s) -
Radhakrishnan Hema,
Charman W. Neil
Publication year - 2007
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.2007.00474.x
Subject(s) - accommodation , dioptre , astigmatism , monocular , optometry , tilt (camera) , optics , ophthalmology , anisometropia , physics , refractive error , medicine , visual acuity , mathematics , geometry
An experiment is described in which changes in ocular astigmatism were recorded over an accommodation stimulus range of 0–4 D, in the right eyes of a group of 31 normal subjects aged 17–37 years. The visual axes were horizontal and the observation conditions were monocular. Although subjects had a range of spherical ametropia, all had initial astigmatism of 1.0 DC or less. It was found that, for most subjects in the group, astigmatism changed in the with‐the‐rule direction, the mean change being −0.036 DC at axis 176 deg for each dioptre of accommodation response. It is speculated that these changes might reflect increases in lens tilt about a horizontal axis, caused by the combined effects of a slacker zonule and gravity.