Monochromatic, L- and S-cone Modulation Only, L- and M-cone Modulation Only, M and S-cone Modulation Only
Conditions
Keywords
Ocular accommodation, Visual acuity, Physiological optics, Visual psychophysics, Color science
Brief summary
In this experiment, subjects will view shapes on a screen with varying colors and be asked to focus their eyes on the shapes. The shapes will look as though they are jumping to random distances away from the eye. As the subjects focus their eyes on the shapes, the investigators will measure the focus of their eyes using a device called a wavefront sensor. This device uses infrared light to measure the optical properties of the eye in real time. Our goal is to find out how well the eye focuses on different colors. Our broad goal is to better understand how the eye focuses because that process is a major part of having clear and good vision.
Detailed description
In this experiment, subjects will view Gabor patterns on a display through a Badal relay. The Gabor patterns will vary in their color. The colors will be picked to selectively modulate cone photoreceptor activity in different directions in cone contrast space. Subjects will be instructed to accommodate to the patterns while the virtual distance of the screen is manipulated with a focus-adjustable lens. As they do so, the investigators will measure the wavefronts of their eyes using a Shack-Hartmann wavefront sensor.
Interventions
OTHERColor
Each intervention involves showing a participant a stimulus with a particular color on a screen display, and asking the participant to focus their eyes on the stimulus. The 4 colors are: 1) grayscale (L, M, and S-cone modulation), 2) L and S cone modulation only, 3) L and M cone modulation only, and 4) M and S cone modulation only.
Sponsors
Rochester Institute of Technology
National Eye Institute (NEI)
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
No minimum to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Between 18-35 years of age * Normal or corrected-to-normal (glasses/contact lenses) vision.
Exclusion criteria
* Vision worse than 20/20 while wearing glasses / contact lenses. * Fragile or loose teeth (participants need to bite a piece of dental clay to stabilize their heads so that measurements can be taken from their eyes) * Current pregnancy (experiment requires sitting down without moving for stretches of time) * Heart disease * Personal/familial history of epilepsy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Accuracy of ocular accommodation | Because this is a basic science experiment, each measurement takes place at the same time as the intervention. There will be two sessions, each lasting approximately 1 hour, on separate days (day 1 and day 2). | Ocular accommodation is the focusing response of the lens in the eye. When the stimulus viewed by the participant changes in distance, the eye automatically refocuses. The investigators measure this refocusing using a device called a wavefront sensor. The investigators are particularly interested in how accurate this refocusing is, which is measured in units of diopters. |
| Speed of ocular accommodation | Because this is a basic science experiment, each measurement takes place at the same time as the intervention. There will be two sessions, each lasting approximately 1 hour, on separate days (day 1 and day 2). | The investigators are interested in how quickly the eye refocuses when a near object moves farther away. Typically, this process takes around 1 second, but it can take longer or shorter depending on the individual and on the object being viewed. By analyzing data collected by the wavefront sensor, the investigators will calculate how long it took for the eye to refocus during each measurement. |
Countries
United States
Contacts
CONTACTBenjamin M Chin, Doctorate
Outcome results
None listed