Abstract
Purpose: :
Quality of vision through a contact lens is affected by on-eye nominal decentrations and dynamic positional changes of the lens. The purpose of the current study was to quantify the positional and corresponding real-time optical changes of rotationally stabilized soft contact lenses during normal wear periods.
Methods: :
Simultaneous high-speed (16hz) videography and whole-eye aberrometry (5mm) were collected over a 10 second wear period including blinking, on 20 dilated eyes wearing 3 different thin-zoned (TZ) and 3 different prism-ballasted (PB) commercially available rotationally stabilized contact lens designs. All lenses were worn in -3, -6, and +4 D powers and contained -0.75Dx180 of cylinder. Each eye wore a total of 18 lenses. A lens-only aberrometer was used to measure the off-eye lens optics. Data from left eyes was converted to right eye equivalent. To describe changes in image quality during typical wear image quality metrics were used.
Results: :
TZ designs had an ave±std nominal decentration from pupil center of 0.48±0.19 temporally and 0.35±0.52mm inferiorly, while PB lenses decentered 0.67±0.18 temporally but 0.26±0.33mm superiorly. Maximal change in decentration during the wear period for both lens types was quite similar. TZ lenses were nominally rotated 0.61±6.06 degrees temporally, and varied 3.48±3.53 degrees from this position, while PB lenses were nominally rotated 18.24±18.21 degrees temporally and varied 6.82±3.52 degrees from this position. Visible changes in higher-order wavefront reconstructions and image quality simulations are induced by these static and dynamic mispositions.
Conclusions: :
TZ and PB lenses dynamically position differently when on the eye, causing differences in attainable image quality for their wearers.
Keywords: contact lens • aberrations