Evaluating How Well Different Types of Light-sensitive Cells in the Eye Contribute to Its Focusing Ability

July 6, 2026 updated by: Benjamin Chin, Rochester Institute of Technology

A Randomized, Repeated-measures Study to Evaluate the Contributions of Different Cone Photoreceptor Classes to a Step Ocular Accommodation Task

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.

Study Overview

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.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Benjamin M Chin, Doctorate
  • Phone Number: 8454534320
  • Email: bmccis@rit.edu

Study Locations

    • New York
      • Rochester, New York, United States, 14623
        • Chester F. Carlson Center for Imaging Science
        • Contact:
          • Benjamin M Chin, Doctorate
          • Phone Number: 8454534320
          • Email: bmccis@rit.edu
        • Principal Investigator:
          • Benjamin M Chin, Doctorate

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Color variation in visual stimulus
Each participant undergoes all experimental conditions, in a within-subjects design. Each intervention corresponds to a different stimulus color. 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.
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Accuracy of ocular accommodation
Time Frame: Each measurement takes 3 seconds. In the experiment, there will be two sessions, each lasting approximately 1 hour, on separate days. In each session, a total of 420 measurements will be taken.
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.
Each measurement takes 3 seconds. In the experiment, there will be two sessions, each lasting approximately 1 hour, on separate days. In each session, a total of 420 measurements will be taken.
Speed of ocular accommodation
Time Frame: Each measurement takes 3 seconds. In the experiment, the investigators will take measurements over the course of two sessions, each on separate days and lasting approximately 1 hour. During each session, 420 measurements will be collected.
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.
Each measurement takes 3 seconds. In the experiment, the investigators will take measurements over the course of two sessions, each on separate days and lasting approximately 1 hour. During each session, 420 measurements will be collected.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 2, 2026

Primary Completion (Estimated)

December 15, 2026

Study Completion (Estimated)

December 15, 2026

Study Registration Dates

First Submitted

June 30, 2026

First Submitted That Met QC Criteria

July 6, 2026

First Posted (Actual)

July 9, 2026

Study Record Updates

Last Update Posted (Actual)

July 9, 2026

Last Update Submitted That Met QC Criteria

July 6, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB0000131-Exp1
  • 4R00EY036497-03 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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