View clinical trials related to Vision Disorders.
Filter by:The purpose of this study is to evaluate how visual acuity assessed with Peek Acuity (a cell phone application to check visual acuity) among preschool and school-aged children 3 to less than18 years of age (1) compares to the standard visual acuity exam in the ophthalmology clinic and (2) performs as a screening test for ocular abnormalities that warrant referral for an eye exam.
The effect of tinted filters and illumination on the visual performance of patients with low vision (i.e., individuals with reduced vision that is uncorrectable with glasses, surgery or treatments) has been a topic of research and discussion for many years, yet there is no current consensus or practice standard for the evaluation and recommendation of colored filters and/or illumination intensity. Anecdotally, there have been many subjective reports of improvement in visual function and comfort with the use of tinted lenses. Previous studies have attempted to elucidate the subjective improvements observed using vision tests, such as visual acuity and contrast sensitivity, and the findings have been inconsistent. Traditionally, filters and optimal illumination are prescribed clinically through a trial and error method, which involves trying various filters and lamps haphazardly to determine which if any are preferred by the patient. The investigators are proposing to evaluate whether the illumination and filters chosen in office by participants using a new assessment tool the LuxIQ/2 translate to overall patient comfort and improved speed, accuracy and print size while reading, and to evaluate whether participants have the same illumination and colored filter preference determined by the LuxIQ/2 in a clinical office setting and in their home environment. The investigators will evaluate whether participants prefer lighting determined by the new assessment tool the LuxIQ/2 in comparison to lighting determined by the OttLite Cobra in office.
Individuals operated for rhegmatogenous retinal detachment will be prospectively evaluated for postoperative retinal shift. Fundus autofluorescence will be used to evaluate retinal shift that will be correlated to visual acuity, metamorphopsia, aniseikonia, and stereopsis.
A) The main purposes of this study are (i) to develop a related virtual reality (VR) environment in order to judge the nighttime driving ability under mesopic and under glare conditions (ophthalmologically healthy subjects and patients with incipient to intermediate cataract, i.e. opacities of the human lens, will participate in this study), (ii) to validate the above-mentioned VR environment with respect to a related on-road driving scenario under mesopic and glare conditions, (iii) to validate clinical photopic and mesopic contrast vision tests and glare tests with respect to the prediction of nighttime driving ability, (iv) to assess the test retest reliability of clinical photopic and mesopic contrast vision tests B) Background: An intact mesopic vision and a glare sensitivity within a normal range are essential pre-requisites for safe driving at nighttime (DOG & BVA, 2011). Anderson & Holiday (1995) have shown that (simulated) opacities of the refractive media (with only minor effects on daytime visual acuity) induce a pronounced impairment of contrast sensitivity under nighttime conditions. Especially under glare conditions by the headlights of traffic on the opposite lane or by stationary street illumination, an impairment of the mesopic vision may cause traffic hazards. The prevalence of impairments of the central visual acuity, the mesopic vision and the glare sensitivity is significantly higher for subjects being involved in nighttime traffic accidents (Lachenmayr, 1998). Furthermore, these impairments occur more frequently in aged drivers and are, among others, related to an increase of age-related media opacities (Aulhorn & Harms, 1970, Babizhayev, 2003). Due to the demographic change, the relevance of nighttime driving ability is increasing in the next years since more and more aged employees will participate at the motorized traffic at night. The German Fahrerlaubnisverordnung (FEV i.e. driving license regulation) specifies pass/fail criteria with regard to mesopic vision and glare sensitivity. The luminance level during nighttime driving is usually between 0.01 and 1 cd/m^2, and therefore can be attributed to the level of mesopic vision. However, over the last years, the attempt was made to introduce photopic contrast sensitivity test to diagnose nighttime driving ability (i.e. testing of contrast vision under daytime conditions without time consuming adaptation procedures). Current research aims at investigating the relationship between contrast tests under various luminance conditions (Wilhelm et al, 2013). It is questionable, whether photopic tests are at all reliable predictors with regard to nighttime driving (Gramberg-Danielsen et al., 1984, Hertenstein et al., Graefe´s Archive of Ophthalmology, 2016).
This study will train participants (young people and older adults) to do a visual task, and will assess whether this results in changes in behavioral assessments. In some participants, we will be also testing whether MRI measures (cortical thickness, functional connectivity) change with training.
This study evaluates the safety and efficacy simultaneous, trans-conjunctival, 25-Gauge vitrectomy and phacoemulsification with intraocular lens implant in patients with metamorphopsia and visual impairment due to idiopathic epiretinal membrane and cataract. All 30 patients recruited underwent complete ocular examination, visual acuity measurement with ETDRS, metamorphopsia assessment with M-Charts and Metamorphometry® and foveal thickness evaluation by sd-OCT preoperatively, at 30, 90, 180 days postoperatively.
This pilot study aims to assess the interest to add an auditory pathway morphological analysis during the MRI exploration of visual pathway in visually impaired children.
This is a randomised controlled trial with the aim of testing the efficacy of coloured overlays and coloured lenses for the relief of visual stress and reading difficulties in children and young adults.
This study will compare near clinical oculomotor parameters (heterophoria, vergence ranges, AC/A and accommodative findings) measured when lenses and/or prisms are introduced using three different instruments namely: (i) a standard manual phoropter, (ii) an electronic phoropter and (iii) a wearable adaptive refractor (VisionFit).
This study is a multi-site, 5-visit dispensing, bilateral double-arm parallel group design, double-masked clinical trial using an investigational contact lens and a marketed contact lens. The objective is to evaluate comfort of the contact lenses when worn on a daily wear modality.