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NCT Number: NCT07001124

Comparative Efficacy of Duochrome Test Verse +1 Blur Test in Detecting Refracting Error Across Different Ages

The comparative efficacy of the duochrome test versus +1 blur test in detecting refractive errors across different ages remains under-explored in current ophthalmic research. While the duochrome test is widely used to refine prescriptions, its standalone effectiveness compared to +1 blur test based refraction has not been thoroughly investigated.

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Key information

Conditions

Refractive Errors Eye Diseases

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Eye professionals clinic (14-S DHA Phase 2 Ghazi road)

Lahore, Punjab Province, Pakistan

About this study

This study aims to evaluate the efficacy, accuracy, and reliability of the duochrome test in identifying refractive errors, including myopia and hyperopia across various ages. Refractive errors, including myopia, hyperopia, and astigmatism, are leading causes of visual impairment, requiring precise diagnostic tools. The duochrome test utilizes chromatic aberration to refine prescriptions, whereas the +1 blur test assesses spherical correction accuracy. Despite their clinical use, direct comparative studies remain limited. A total of 33 participants with estimated 10% dropout randomly assigned to undergo both tests. Groups will be based on different ages, Group A (18-35 years)and group B (36-60 years) ..both test (Duochrome test and +1 blur test) will apply on every patients.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Age between 18 to 60 years old.
  • Both genders.
  • Those who have refractive error.
  • Patients with no history of prior eye surgery.
  • No active eye diseases affecting visual acuity, such as cataracts or retinal disorders.
  • Ability to cooperate with both the duochrome test and +1 blur test.

Exclusion criteria

  • Patients with severe visual impairment or neurological conditions affecting vision.
  • Patients with nystagmus or conditions that could interfere with reliable testing.
  • Age below 18 year and above 60 year excluded
  • Those patients who don't show their consent.

Treatment and study plan

duochrome test and +1 blur test

Diagnostic Test

The participant is seated at a standard testing distance (typically 6 meters or 20 feet). A duochrome chart with black letters on a split red-green background is presented.

After determining the subjective refraction, a +1.00 diopter (DS) lens is added to the final prescription. The participant is asked to read the distance visual acuity (VA) chart. The expectation is that the visual acuity should drop to 4 lines on Snellen chart (6/24) when the +1.00 DS lens is added. If VA reduces to 6/24: Indicates that the refraction is not over-minused or over-plussed (proper end point of refraction). If VA remains better than 6/24: Suggests the patient was still accommodating, possibly leading to over-minus (in myopes) or under-plus (in hyperopes) and the refraction should be re-evaluated.

Primary outcomes

  1. Visual Function Index (VF-14) Questionnaire:

    Time frame: 12 Months

    Scores on all activities that the person performed or did not perform because of vision were then averaged, yielding a value from 0 to 4. This value was multiplied by 25, giving a final score from 0 to 100. A score of 100 indicates able to do all applicable activities score of 0 indicates unable to do all applicable activities because of vision

  2. +1 blur test

    Time frame: 12 Months

    Adding a +1.00 diopter (DS) lens to a patient's final refraction and measuring their distance visual acuity (VA). There are 4 questions with 5 different options ranging from 0-4. minimum score is 0 and maximum score is 16 with spherical correction.

  3. Duochrome Test

    Time frame: 12 Months

    A duochrome test chart .There are 4 questions with 5 different options ranging from 0-4. minimum score is 0 and maximum score is 16 with spherical correction.

Sponsors and collaborators

Lead sponsor

Superior University

Other

Registry information

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Jun 3, 2025
Registry last updated
Jul 16, 2025

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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