PURPOSE Outstanding improvements in vision can theoretically be expected using contact lenses that correct monochromatic aberrations of the eye. Imperfections in such correction inherent to contact lenses are lens flexure, translation, rotation, and tear layer effects. The effects of pupil size and accommodation on ocular aberration may cause further difficulties. The purpose of this study was ...

In this paper we present experimental results that investigate the integration of two disparate sensing modalities, force and vision, for sensor-based microassembly. By integrating these sensing modes, we are able to provide feedback in a task-oriented frame of reference over a broad range of motion with an extremely high precision. An optical microscope is used to provide visual feedback down ...

The aim of this study was to calculate the level of improvement of visual acuity comparing the best corrected visual acuity (VA) achieved with spectacles with the best corrected VA achieved with rigid gas permeable (RGP) contact lenses in patients with high, simple or compound corneal astigmatism (myopic, hypermetropic and mixed). The investigation of patients included auto-kerato-refractometry...

PURPOSE To investigate the medical profiles of patients referred to Iran Lens Clinic with myopic/myope-astigmatic refractive errors. METHODS Medical records of 182 patients (364 eyes) with myopic/myope-astigmatic refractive errors that underwent orthokeratology contact lens wear and fulfilled a 6-month period of follow-up were recruited. Efficacy and safety of these contact lenses in improvin...

BACKGROUND The aim of the study was to examine the clinical success of high Dk (oxygen permeability) piggyback contact lens (PBCL) systems for the correction of contact lens intolerant keratoconus patients. METHODS Sixteen patients (29 eyes) who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen transmissibility or Dk/t = 150 units...

Objectives To investigate the visual and ocular implications of continuous wearing a silicon hydrogel contact lens for up to 3 weeks , in a dry semi-arid climate environment. Methods Clinical examination of eye conditions (visual acuity, Schirmer test, corneal thickness and endothelial cells counts) for 9 healthy voluntary students was carried out between September and November of 2004 in Riyad...

A 23-year-old lady was referred to the cornea clinic complaining of progressive visual loss from 8 years ago. Uncorrected visual acuity (UCVA) was 20/100 in her right eye and 20/600 in the left one. She was using rigid gas-permeable (RGP) contact lenses for 4 years and complained of contact lens intolerance especially in her left eye. On slit lamp examination, both corneas were clear but Vogts’...

This is the report of a case of bilateral Acanthamoeba keratitis in a 19-year-old woman who bought a pair of disposable soft contact lenses in a boutique. She wore this same pair of lenses for 3 months daily without the appropriate care. This led to bilateral corneal transplantation with cataract extraction and also trabeculectomy in the right eye. When last seen, both grafts were crystal clear...

How the visual cortex responds to specific stimuli is strongly influenced by visual experience during development. Monocular deprivation, for example, changes the likelihood of neurons in the visual cortex to respond to input from the deprived eye and reduces its visual acuity. Because these functional changes are accompanied by extensive reorganization of neurite morphology and dendritic spine...

PURPOSE To evaluate the clinical efficacy and complications of intraocular lens (IOL) exchange. METHODS A review of medical records was performed for 52 eyes that had undergone an IOL exchange due to IOL opacification. Surgical complications and their incidences were analyzed. The mean best corrected visual acuity (BCVA) after the IOL exchange was compared with the mean pre-exchange BCVA and ...