View clinical trials related to Refractive Errors.
Filter by:The purpose of this study is to assess the clinical performance of two reusable silicone hydrogel contact lenses when worn on a daily wear basis.
The purpose of this clinical trial was to evaluate the clinical performance of a manufacturing process on a frequent replacement multifocal contact lens.
Identification of the correlation between angle kappa , corneal high order aberrations and total eye aberrations in myopic hyperopic and astigmatic patients
The clinical investigation objective is to evaluate safety and performance outcomes of trifocal IOL implantation to improve vision in patients with cataract and/or ametropia (hyperopia, myopia) and/or presbyopia. Retrospective data from preoperative status up to 12 month postoperative status will be collected from patients that were implanted with Medicontur's 640PM intraocular lens: - Preoperative status: Preoperative Screening and Baseline - Surgery: IOL implantation - M1: 1 month +/- 2 weeks postoperative follow-up - M3: 3 months +/- 1 month postoperative follow-up - M12: 12 months +/- 3 months postoperative follow-up
This is a 12-month longitudinal randomized controlled trial aiming to evaluate the effect of colour temperature of reading lamp on refractive error development.
The purpose of this clinical trial is to evaluate the effect of light-emitting diodes (LEDs) with a continuous spectrum of 430-780 nm for lighting in the classroom on myopia prevention among children in Grades 2 and 3.
The objective of this intervention study was to understand the visual health status of nearly one million children and adolescents in ten provinces in China, and then to conduct intervention and evaluate the effect of intervention measures with the development of myopia as the outcome indicator. The study will be conducted in the form of a stepped intervention and will answer the following questions. Current China children and adolescent's vision health, including the different degrees of myopia prevalence, and farsightedness reserve status. To evaluate the implementation and effect of eight appropriate technologies and six interventions developed in this study, to reduce the incidence of myopia among children and adolescents in China, to achieve the purpose of nationwide application. In the early stage of this study, a baseline survey will be conducted on participants. In the middle stage, participants will be required to adjust the seat height regularly and increase the time for outdoor activities, etc. In the later stage, intervention measures will be evaluated based on the overall research situation to consider national promotion.
This study will be a 2-phase, prospective, multicenter, open-label, non-comparative, non-randomized clinical investigation to confirm the safety and effectiveness of the ELITA system.
A prospective, self-control, double-blind design was conducted in Tianjin. Two hundred participants were assigned to wear two kinds of spectacle glasses. To examine the effect of free-toroidal design and aspherical lens on the subjective visual quality among the myopic population.
This prospective non-comparative interventional study aims to analyse the pre-operative factors affecting the range of optimal ICL vaulting. the main question is what is the correlation between age, gender, spherical equivalent, white to white, anterior chamber volume and depth and postoperative vault? participants will do preoperative investigations ( specular microscopy, pentacam and biometry ) then refractive surgery (ICL implantation) followed by follow-up visits to assess the post-operative ICL vault and visual outcome.