Measuring How Quickly the Eye Focuses After Sustained Viewing of Close-up Images and Videos

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

A Randomized, Repeated-measures Study to Measure the Temporal Frequency Response of Ocular Accommodation After Sustained Near Viewing.

In this experiment, subjects will view a cross pattern on the screen and be asked to focus their eyes on it. The cross pattern will look like it is moving towards and away from the eye in a back-and-forth motion. 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 before and after viewing images on a screen up close (25cm). Since many people spend a lot of time looking at a computer screen while at work or at school, it is important to understand how this affects the eye's ability to focus.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

In this experiment, subjects will view a Maltese cross pattern on a display through a Badal relay. Subjects will be instructed to accommodate to the pattern while a focus-adjustable lens optically moves the display closer and farther in depth as a sinusoidal function of time. As they do so, the investigators will measure the wavefronts of their eyes using a Shack-Hartmann wavefront sensor. The investigators will measure the gain and phase of the accommodative response of the subjects' eyes. Measurements will be made before and after sustained viewing of images on a computer screen 25cm away.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Benjamin M Chin, Doctorate
  • Phone Number: 8454534320
  • Email: bmccis@rit.edu

Study Locations

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

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • 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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Near viewing first first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. There are two types of sessions: one in which the screen is viewed first ('near viewing first'), and the other in which the distant object is viewed first ('distant viewing first'). All participants do both sessions. However, in one arm, participants do the 'near viewing first' session first.
Other: Near viewing first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. In one intervention, the session is structured such that the screen is viewed first ('near viewing first').
Other: Distant viewing first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. In one intervention, the session is structured such that the distant object is viewed first ('distant viewing first').
Experimental: 'Distant viewing first' first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. There are two types of sessions: one in which the screen is viewed first ('near viewing first'), and the other in which the distant object is viewed first ('distant viewing first'). All participants do both sessions. However, in one arm, participants do the 'distant viewing first' session first.
Other: Near viewing first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. In one intervention, the session is structured such that the screen is viewed first ('near viewing first').
Other: Distant viewing first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. In one intervention, the session is structured such that the distant object is viewed first ('distant viewing first').

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Gain and phase of ocular accommodation
Time Frame: Each measurement takes 10 seconds. In the experiment, the investigators will take measurements over the course of approximately 1 hour.
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 the gain of accommodation, which is the ratio of the amplitude of accommodation to the amplitude of sinusoidal changes in stimulus distance. The investigators are also interested in the phase of the accommodative response, which is related to the lag of the accommodative response.
Each measurement takes 10 seconds. In the experiment, the investigators will take measurements over the course of approximately 1 hour.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Rochester Institute of Technology

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Eye Institute (NEI)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Benjamin M Chin, Doctorate, Rochester Institute of Technology

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 25, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 25, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 25, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 1, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB0000131-Exp2
  • 4R00EY036497-03 (U.S. NIH Grant/Contract)

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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