BACKGROUND The purpose of this study was to evaluate the effect of daily administration of mannitol-enriched sodium hyaluronate ophthalmic solution on the corneal optical properties of subjects wearing low Dk hydrogel (etafilcon A) contact lenses (CLs). METHODS Forty-five subjects wearing etafilcon A CLs daily for more than 6 months were recruited into this pilot study. Fifteen of the subject...

As semiconductor lithography is pushed to smaller dimensions, process yields tend to suffer due to subwavelength topographical imaging effects. Three dimensional or “thick mask” effects result in such things as a pitch dependent best focus and, for alternating phase shift masks (AltPSMs), an intensity imbalance between etched and un-etched features. Corrective mask structures such as the dual t...

Though the human eye generally creates a single image on the retina, the literature contains many examples showing perceptual monocular diplopia. Previously, monocular diplopia resulting from astigmatic defocus has been demonstrated to cause a notch (local minimum) in the contrast sensitivity function (CSF). We examine Verhoeff's (1900) model which explains how monocular diplopia can occur thro...

PURPOSE To evaluate the differences of wavefront aberrations under cycloplegic, scotopic and photopic conditions. METHODS A total of 174 eyes of 105 patients were measured using the wavefront sensor (WaveScan® 3.62) under different pupil conditions: cycloplegic 8.58 ± 0.54 mm (6.4 mm - 9.5 mm), scotopic 7.53 ± 0.69 mm (5.7 mm - 9.1 mm) and photopic 6.08 ± 1.14 mm (4.1 mm - 8.8 mm). The pupil ...

PURPOSE To compare changes in the corneal wavefront aberrations after photorefractive keratectomy and laser in situ keratomileusis. METHODS In a prospective randomized study, 22 patients with bilateral myopia received photorefractive keratectomy on one eye and laser in situ keratomileusis on the other eye. The procedure assigned to each eye and the sequence of surgery for each patient were ra...