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

Conditions

• After 20 Minutes of Far Viewing
• After Sustained Near Viewing of Computer Display for 20 Mins

Eligibility Criteria

Sex

ALL

Age

N/A - 35 Years

Healthy Volunteers

Accepted

Interventions

• Near viewing first — OTHER
  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').
• Distant viewing first — OTHER
  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').

Study Details

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.

Key Dates

Start date

Jun 25, 2026

Status verified

Jun 2026

Primary completion

Dec 15, 2026

Completion

Dec 15, 2026

Study Design

Enrollment

20 participants (estimated)

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Arms

• 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.
• 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.

Primary Outcome Measure

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. ]

Central Contacts

• Benjamin M Chin, Doctorate
  8454534320
  [email protected]

Locations (1)

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