View clinical trials related to Refractive Errors.
Filter by:Refractive surgeries can be divided into two distinct categories: 1) corneal surgeries (superficial and deep procedures) carried on the surface of the eye and 2) lens surgeries (phakic IOL, refractive lens exchange) - an intraocular intervention, performed in the anterior or posterior chamber or on the lens. In the proposed protocol focus is on the corneal refractive surgeries impact on monochromatic higher-order aberrations on the one hand and chromatic aberrations on the other. During the surgery in order to get the patient emmetropic, refractive surgery corrects optical defects by decreasing aberrations of lower orders ) simultaneously increases high-order aberrations (that is perceived by the patient as halo, glare or starburst). Informations about prevalence and causes of higher order aberrations after refractive surgery are numerous but there is no information about chromatic aberrations.
The study aims to observe the ocular development and refractive error changes among school children and adolescents
Study to evaluate the safety and efficacy of HI-BRITE large diameter rigid gas permeable contact lens (hexafocon b) test when worn on a daily wear basis in the correction of myopia/hyperopia/astigmatism/presbyopia/ and irregular cornea.
The purpose of this study is to utilize in-vivo confocal microscopy to describe differences in corneal epithelial immune status across three lens care regimens in new contact lens wearers.
This is a multicenter study to evaluate the clinical performance of the SynergEyes A2 lens in patients with refractive errors with or without astigmatism.
Axial hyperopia results when the length of the eye is too short for the eye to properly focus distance objects on the retina while the focusing system is relaxed. Emmetropization is the process by which the eye actively adjusts various components of the eye to gradually improve the focus of the eye. Emmetropization frequently involves either an increase or a decrease in the growth of the eye, particularly during infancy and childhood. Numerous animal studies suggest that if an animal is exposed to retinal images located behind the retina either centrally or peripherally, the eye will grow in the direction of the focused image. If an abnormally short eye has resulted in hyperopia, exposing such an eye to retinal images partially located behind the retina might encourage axial elongation, thus reducing the hyperopia.
The aim of this study is to examine the relationship between optical blur from poor refractive corrections (glasses) of workers using computers and their productivity and comfort in the workplace. We believe that improving the visual status of subjects who use computers will have a beneficial effect on productivity and visual comfort.
To identify vision-screening tests that can accurately predict those three- and four-year old preschoolers who would benefit from a comprehensive vision examination because of signs of amblyopia, strabismus, and/or significant refractive error.