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NCT Number: NCT06753032

Impact of Positive & Negative Lens-Induced Defocus on Contrast-Sensitivity in Myopic & Non-Myopic Adults

examines the influence of lens-induced defocus on contrast sensitivity-a crucial aspect of visual performance.Each participant experiences both positive and negative defocus through different lenses, with measurements taken for contrast sensitivity using the Pelli-Robson chart. Outcomes are evaluated at baseline, 2 weeks, and 4 weeks to understand the effect of defocus over time.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

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Key information

Conditions

Myopia Eye Diseases Refractive Errors

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Tehsil Headquarters (THQ)

Taunsa, Punjab Province, Pakistan

About this study

Additional data on symptoms like visual fatigue and computer vision syndrome are gathered using the Visual Fatigue Questionnaire (VFQ) and the Computer Vision Syndrome Questionnaire (CVS-Q), respectively. This study's findings could be instrumental in refining optical treatments, offering insights into how defocus impacts visual function across refractive conditions. Results may ultimately benefit optometric practices by guiding lens prescriptions for improved contrast sensitivity and quality of life for myopic and non-myopic individuals alike.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged 18 to 50 years.
  • Participants with a confirmed diagnosis of myopia or non-myopia.
  • Best corrected visual acuity of 20/30 or better.
  • No history of ocular surgery or significant ocular disease.
  • Informed consent was obtained.

Exclusion criteria

  • Individuals with a history of systemic diseases affecting vision (e.g., diabetes, hypertension).
  • Presence of binocular vision anomalies or strabismus.
  • Pregnant or nursing women.
  • Any current use of medications affecting visual function (e.g., medications causing visual side effects).

Treatment and study plan

Positive Lens-Induced Defocus Using Spectacle Lenses (+2.00 D) for Myopic Participants

Diagnostic Test

Intervention Description: This group will be exposed to positive defocus induced by +2.00 D spectacle lenses. The lenses are designed to create optical blur to evaluate the effects on contrast sensitivity and visual fatigue. Measurements will be conducted at baseline, 2 weeks, and 4 weeks after exposure to assess changes in visual function."

Negative Lens-Induced Defocus Using Spectacle Lenses (-2.00 D) for Myopic Participants

Diagnostic Test

Intervention Description: This group will be exposed to negative defocus induced by -2.00 D spectacle lenses. The induced defocus will allow for the evaluation of its impact on contrast sensitivity and visual fatigue. Assessments will be carried out at baseline, 2 weeks, and 4 weeks."

Positive Lens-Induced Defocus Using Spectacle Lenses (+2.00 D) for Non-Myopic Participants

Combination Product

ntervention Description: This group will undergo positive defocus using +2.00 D spectacle lenses. The intervention aims to examine the effect of induced defocus on contrast sensitivity and visual fatigue in non-myopic participants. Data will be collected at baseline, 2 weeks, and 4 weeks."

Negative Lens-Induced Defocus Using Spectacle Lenses (-2.00 D) for Non-Myopic Participants

Combination Product

Intervention Description: This group will experience negative defocus induced by -2.00 D spectacle lenses. The purpose is to evaluate how negative lens-induced defocus affects contrast sensitivity and visual fatigue in non-myopic participants. Measurements will be taken at baseline, 2 weeks, and 4 weeks.

Primary outcomes

  1. Contrast Sensitivity

    Time frame: 12 Months

    Measured with the Pelli-Robson Contrast Sensitivity Chart, capturing changes in participants' ability to detect low-contrast visual stimuli under defocus conditions.

  2. Visual Fatigue

    Time frame: 12 months

    Evaluated with the Visual Fatigue Questionnaire (VFQ) and Computer Vision Syndrome assessing symptoms like eye strain, discomfort, and fatigue following lens-induced defocus.

Sponsors and collaborators

Lead sponsor

Superior University

Other

Registry information

Important dates

Study start
2024
Primary completion
2024
Study completion
2025
First posted
Dec 31, 2024
Registry last updated
Dec 31, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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