Impact of Glasses for Vision Problems on Cognitive Function in Rural Older Adults (CLEVER)

May 12, 2026 updated by: Yuju Wu

The Impact of Spectacle Intervention for Refractive Error and Presbyopia on Cognitive Function in Rural Older Adults

The aim of this project is to explore whether vision correction can effectively slow cognitive decline in older adults.

The primary question it seeks to answer is: Can providing free near and/or distance vision correction glasses to older adults with refractive errors or uncorrected vision, who have normal baseline cognition and hearing, reduce the rate of cognitive decline over 36 months in a cost-effective manner? Researchers will compare the rate of cognitive decline over 36 months between older adults who receive refractive correction and those who do not.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

964

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

Study Locations

    • Sichuan
      • Ya'an, Sichuan, China, 610065
        • Recruiting
        • Community health service centers
        • Contact:
          • Yuju Yingjing County Health Commission
          • Phone Number: 0835-7623834
          • Email: yujuwu@scu.edu.cn

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Older adults who meet all of the following criteria will be eligible to participate in this study:

    • Registered as a rural resident (holding rural household registration);
    • Age from 60 to 79 years at the time of enumeration;
    • Resident in the household for > = 3 months and planning to reside in the local area for the trial duration;
    • Distance vision impairment (VI, presenting visual acuity [VA] < 6/12 in the better-seeing eye and improving to ≥ 6/7.5 or better in either eye with spectacle correction) and/or near VI (presenting near VA < 6/12 at 40 cm when measured binocularly and improving to ≥ 6/7.5 or better in either eye with near correction);
    • Independent mobility with or without the support of a walking stick;
    • Chinese version of the Mini-Mental State Examination (C-MMSE) score above the following cut-offs (out of 30): >17 for illiterate participants, >20 for those with primary school education, >22 for those with junior high school education, and >23 for those with high school education or above.
    • Willingness to participate, to be randomized to either study group, and to adhere to the protocol

Exclusion Criteria:

  • Presence of glaucoma or visually significant cataract, or a history of surgical treatment for these or other major ocular conditions;
  • Consistent use of prescription spectacles and/or hearing aids;
  • Serious medical illness likely to result in loss to follow-up. Those less severely affected by conditions such as hypertension and/or diabetes will be eligible;
  • Failure on the whispered voice hearing screening test in the better ear (unable to repeat > = 3 out of 6 words whispered from behind the participant at a distance of 50 cm);

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Free Prescription Glasses Intervention group
All participants randomly assigned to the intervention group will receive free near or distance vision correction glasses based on their refractive error. Participants can choose from a variety of frames, and the research team will customize the glasses according to their pupillary distance and prescription. Once the glasses are ready, they will be provided to the participants following standard usage instructions. In case of loss or damage, participants should report it to the project team and will be provided with replacement glasses as needed. Each year, participants in the intervention group will undergo an eye exam to assess changes in vision, and their glasses prescription will be updated if necessary.
Participants can choose from a variety of frames, and the research team will customize the glasses according to their pupillary distance and prescription. Once the glasses are ready, they will be provided to the participants following standard usage instructions. In case of loss or damage, participants should report it to the project team and will be provided with replacement glasses as needed. Each year, participants in the intervention group will undergo an eye exam to assess changes in vision, and their glasses prescription will be updated if necessary.
No Intervention: Prescription-Only Control group
All participants randomly assigned to the control group will receive an eyeglass prescription, but free glasses will not be provided during the study. At the end of the study, the research team will provide near or distance vision correction glasses free of charge based on the needs of the control group participants.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
**Chinese version of the Global Cognitive Score Scale**
Time Frame: Each participant will undergo cognitive assessments at baseline, 12 months, 24 months, and 36 months to evaluate the impact of the intervention on cognitive decline.
The primary endpoint is the change in cognitive function over three years, which is comprehensively determined using the Chinese version of the Global Cognitive Score Scale-by administering the Chinese version Mini-Mental State Examination (C-MMSE), Beijing version of the Montreal Cognitive Assessment (MoCA), Telephone Interview for Cognitive Status (TICS), Community Screening Instrument for Dementia Interviewee Part (CSI-D), and Number Series Test.
Each participant will undergo cognitive assessments at baseline, 12 months, 24 months, and 36 months to evaluate the impact of the intervention on cognitive decline.

Collaborators and Investigators

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

Sponsor

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 (Actual)

November 10, 2025

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2030

Study Registration Dates

First Submitted

February 12, 2025

First Submitted That Met QC Criteria

February 19, 2025

First Posted (Actual)

February 20, 2025

Study Record Updates

Last Update Posted (Actual)

May 14, 2026

Last Update Submitted That Met QC Criteria

May 12, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • HXSY-BEC-S2026005

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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