Designing lenses to correct peripheral refractive errors of the eye

Abstract

The purpose of this work was to design ophthalmic lenses that correct peripheral refractive errors of human eyes along a meridian. We designed lenses with the tangential section of one surface based on a figured spheroid but figured in the tangential section only. The curvature of the sagittal section of this surface was adjusted separately. A merit function was used to modify these surfaces until the lenses had power errors that corrected the eye. Examples are presented of lenses that correct a schematic eye. They do excellent jobs of correcting the peripheral power errors of the eye and are relatively insensitive to small changes in fitting distance. We conclude that it is theoretically feasible to design lenses to correct peripheral refractive errors.

Visual Performance with Lenses Correcting Peripheral Refractive Errors

“…34 Sankaridurg et al 21 described three designs of spectacle lenses to manipulate peripheral refraction in children with myopia. In terms of correcting the optics at a range of locations, we designed lenses to correct schematic eyes along one meridian of the visual field in a previous work.…”

The effect of instrument alignment on peripheral refraction measurements by automated optometer

“…This is particularly important in studies designing ophthalmic lenses that correct peripheral refractive errors of human eyes for the purpose of reducing myopia progression. Imprecise alignment of the instrument when measuring relative hyperopia in myopic subjects may lead to inaccurate manipulation of the curvature of the image shell with these novel spectacle lenses 18,26 …”

“…Imprecise alignment of the instrument when measuring relative hyperopia in myopic subjects may lead to inaccurate manipulation of the curvature of the image shell with these novel spectacle lenses. 18,26 By fitting a quadratic function for each fixation angle, we can predict an ideal alignment position based on the accuracy and precision of the mean spherical equivalent and cylindrical power. Our data suggest that operators can be confident in the accuracy and precision of both central and peripheral autorefractor measurements, whether the instrument is aligned with the centre of the pupil or the corneal reflex, provided that the alignment mark of the instrument is in clear focus.…”

Influence of Fogging Lenses and Cycloplegia on Peripheral Refraction

“…21 Peripheral refraction has also been studied with the goal of obtaining a theoretical model of the ophthalmic lenses that could correct the peripheral refractive error. 25 Refractive error in the peripheral retina, as compared to central refraction, shows a myopic trend in emmetropes and hyperopes. On the other hand, myopes present a peripheral refraction that is less myopic or more hyperopic than the central measurement; 4,5,26 this fact has been more intensively studied for the horizontal meridian of the eye.…”