Normal Healthy Eyes
Conditions
Brief summary
Eye's aberrations have been known to degrade human visual performance and the visual performance is significantly improved when correcting the aberrations in the central visual field. However, how the aberration correction affects the peripheral visual performance is not well understood. Moreover, how central and peripheral vision interacts remains unclear. To conduct the study, we will use an adaptive optics vision simulator equipped with a Shack-Hartmann wavefront sensor and a spatial light modulator (see details in procedures section of the protocol). This system is capable of noninvasively controlling the eye's optical quality and evaluating visual performance simultaneously over a wide area of visual space. This study provides insights into the visual performance in the periphery visual field, and interaction between central and peripheral visual fields. The goal of this study is to evaluate the visual performance at central and peripheral visual fields after correcting the ocular aberrations. An optical system equipped with a liquid crystal spatial light modulator will be used to achieve this goal non-invasively.
Interventions
DEVICESpatial light modulator
This device compensates for the eye's optical imperfections (aberrations) at the foveal and peripheral retina.
Sponsors
University of Houston
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
A person is eligible for inclusion in the study if he/she: * Is between the ages of 18 and 60. * Has normal corneas i.e. no corneal infections, no systemic pink eye, no clinically significant dry eye, and no corneal dystrophies. * Has refractive errors less than +/- 10.0 Diopters in both eyes.
Exclusion criteria
A person will be excluded from the study if he/she: * Adults between the ages of 18-60 who are unable to give informed consent * Individuals below 18 years old * Individuals above the age of 60 * Pregnant women (self-reporting, hormonal changes may alter the refractive status of the eye) * Prisoners * Students for whom you have direct access to/influence on grades * People who do not understand or speak English * Has clinically significant dry eye. * Has clinically significant cataract. * Has spherical refractive error that exceeds the limits outlined above. * Is unable to hold his or her head steady for the duration of study measurements.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Visual acuity | up to 6 separate sessions (each session taking up to 2 hours) | Snellen Tumbling E method will be used to determine the smallest letter that a subject can see. |
| Contrast sensitivity | up to 6 separate sessions (each session taking up to 2 hours) | Light and dark sinusoidal stripes (Gabor gratings) will used to determine the smallest contrast that a subject can see |
| Contrast perception | up to 6 separate sessions (each session taking up to 2 hours) | Light and dark sinusoidal stripes (Gabor gratings) will used to determine differences in contrast perceived by the central and peripheral visual system |
Contacts
Primary ContactGeunyoung Yoon, PhD
Backup ContactJiakai Lyu, MS
Outcome results
None listed