Can Precision UV Mask Astigmatism?

The article "Do Disposable Contact Lenses Mask Astigmatism" by Michael G. Harris O.D., J.D., M.S., and others was published in the May/June 1996 issue of Optical Prism. The article descibed a study in which the masking of astigmatism effect of three lenses were compmed: CSI Clarity (conventional), Accuvue (disposable); and Surevue (disposable). They did not find any significant difference in the amount of astigmatism masked by these three lens types. 1 Now there is a new, thicker disposable contact lens, Precision UV, by Wesley Jessen that may perform better at masking refractive astigmatism. lt is thought that spherical lenses made thicker or of a stiffer polymer can neutralize of mask some corneal cylinder much in the same way that a rigid gas permeable lens does, by creating a tear lens. There have been clinical investigations in the past that have found no statistically significant masking of astigmatism with conventional spherical hydrogels.1 However, there are many anecdotal reports that spherical soft lenses can, and do mask coroeal astigmatism which leads to improved visual acuity. Wesley Jessen has stated that the intended use of Precision UV is "for the correction of visual acuity in not -aphakic persons with non-diseased eyes that are myopic or hyperopic and may have 2.00 diopter (D) or less of corneal astigmatism that does not interfure with visual acuity." 3 Our study was designed to parallel the 1996 study by Dr. Harris to see if this new, thicker lens can mask astigmatis, even up to 2.00 D of corneal astigmatism.