View clinical trials related to Refractive Errors.
Filter by:Youth and some adults have photoscreening refractions and hand-held auto refraction before cycloplegia refraction during new and follow up eye examinations. Vector math is applied to each refraction to determine how closely the hand-held "dry" devices match actual refraction.
The purpose of this clinical study is to assess the safety and performance of an investigational soft contact lens compared to a commercially available soft contact lens when worn in a daily wear modality with frequent replacement.
Main objective Show that the equivalent sphere refraction measurements obtained by the SiVIEW software have no significant clinical difference with those obtained by an optometrist expert. Secondary objectives Show that the sphere refraction measurements obtained by the SiVIEW software have no significant clinical difference with those obtained by an optometrist expert. Show that the cylinder refraction measurements obtained by the SiVIEW software have no significant clinical difference with those obtained by an optometrist expert. Show that the visual acuity measurements obtained by the SiVIEW software do not have a significant clinical difference with those obtained by an optometrist expert. Demonstrate that the report delivered for each eye exam by SiVIEW software is consistent and relevant to a vision health practitioner. Show that the differences obtained between two eye examination experts are consistent with those found in the literature.
The purpose of this clinical study is to evaluate the safety and effectiveness of an investigational soft contact lens compared to a commercially available soft contact lens when worn for daily wear and replaced monthly.
This is a multicenter, prospective, randomized, subject- and evaluator-masked, bilateral-implant study conducted at up to 15 sites worldwide. A total of up to 280 subjects will be randomized in a 1:1 ratio for implantation with either the TECNIS Symfony plus IOL Model ZHR00V or the Trifocal IOL. This will ensure that data from at least 100 subjects in the TECNIS Symfony plus lens group and at least 100 subjects in the Trifocal lens group will be available for analysis at the 6-month follow-up timepoint. All subjects will be followed for up to 6 months postoperative.
This study will provide a profile of blindness/visual impairment, avoidable blindness and cataract surgery service in Chaonan, mainland China. We also evaluate the diagnostic accuracy of Rapid Assessment of Avoidable Blindness (RAAB) comparison with conventional survey.
The purpose of this clinical trial is to evaluate the safety and performance of an investigational soft contact lens compared to a commercially available soft contact lens when worn in an extended wear modality.
This subject-masked, randomized, bilateral crossover study will compare the clinical performance and subjective acceptance of the somofilcon A 1 day soft contact lens with the nelfilcon A daily disposable lens when used on a daily wear, daily disposable basis.
The aim of this work is to investigate the clinical performance and subjective acceptance of the comfilcon A asphere contact lens when compared to single-vision spectacles in subjects who have never worn contact lenses and who use digital devices (such as phones, tablets, laptops, desktop computers) for at least 4 hours per day on at least 5 days per week.
The purpose of this study is to obtain on-eye performance data to inform contact lens product development.