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

June 25, 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, we 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

Recruiting

Conditions

Intervention / Treatment

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, we will measure the wavefronts of their eyes using a Shack-Hartmann wavefront sensor. We 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

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

  • 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

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • We will recruit participants for inclusion who are adults in the age range of 18-35 years, because these are the ages at which people's eyes are able to focus at near distances.

Exclusion Criteria:

  • Participants will be screened for having normal or corrected-to-normal (glasses/contacts) vision. Participants with vision worse than 20/20 will be excluded. People with fragile or loose teeth will be excluded because participants need to bite a piece of dental clay to stabilize their heads so that measurements can be taken from their eyes (too much head and eye movement disrupts the measurement). People who are pregnant, with heart disease, or personal/familial history of epilepsy will be excluded because some studies recommend against them viewing computer displays while sitting down for an extended period of time.

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
Intervention / Treatment
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

Outcome Measure
Measure Description
Time Frame
Gain and phase of ocular accommodation
Time Frame: Each measurement takes 10 seconds. In the experiment, we 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. We measure this refocusing using a device called a wavefront sensor. We 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. We 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, we 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

Rochester Institute of Technology

Collaborators

National Eye Institute (NEI)

Investigators

  • 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)

June 25, 2026

Primary Completion (Estimated)

December 15, 2026

Study Completion (Estimated)

December 15, 2026

Study Registration Dates

First Submitted

June 25, 2026

First Submitted That Met QC Criteria

June 25, 2026

First Posted (Actual)

July 1, 2026

Study Record Updates

Last Update Posted (Actual)

July 1, 2026

Last Update Submitted That Met QC Criteria

June 25, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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