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

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: Cognition Disorders
• Intervention / Treatment: Device: Free Prescription Glasses

Detailed Description

Exploratory subgroup analyses will be conducted to assess whether the intervention effect on cognitive decline differs according to baseline vision correction needs (near vision correction, distance vision correction, or both) and baseline cognitive function. These analyses will be interpreted cautiously due to their exploratory nature.

• Study Type: Interventional
• Enrollment (Estimated): 964
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yuju Wu; Phone Number: 86+18382096899; Email: yujuwu@scu.edu.cn

Study Locations

• China
  • 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

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

How is the study designed?

Design Details

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

Number of Arms

2

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.	Device: Free Prescription Glasses; 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
Change in global cognitive function	The primary outcome will be the change in global cognitive function from baseline to the 36-month follow-up, assessed by the total score of the Chinese version of the Montreal Cognitive Assessment Basic (MoCA-BC) . The MoCA-BC was selected because it minimizes reading and writing requirements and has been widely used in China, allowing for reliable cognitive assessment among individuals who are illiterate or have limited formal education.	Baseline to 12, 24, and 36 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in domain-specific cognitive function	Secondary outcomes include domain-specific cognitive performance derived from a composite cognitive battery based on the China Health and Retirement Longitudinal Study (CHARLS) cognitive assessments. The CHARLS-based cognitive battery comprises a set of task-based cognitive assessments, such as measures of orientation, episodic memory, verbal fluency, and executive function. These tasks rely primarily on oral responses, making them particularly suitable for participants with uncorrected refractive errors, for whom visually demanding tasks may be challenging.	Baseline to 12, 24, and 36 months
Change in falls risk	Falls risk will be assessed using the prespecified falls-risk assessment included in the study protocol.	Baseline to 12, 24, and 36 months
Change in vision-related quality of life	Vision-related quality of life will be assessed using the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25).	Baseline to 12, 24, and 36 months
Change in health-related quality of life	Health-related quality of life will be assessed using the EQ-5D-5L.	Baseline to 12, 24, and 36 months
Change in depressive symptoms	Depressive symptoms will be assessed using the 9-item Patient Health Questionnaire (PHQ-9).	Baseline to 12, 24, and 36 months
Change in physical activity	Physical activity will be assessed using the short form of the International Physical Activity Questionnaire (IPAQ-SF)	Baseline to 12, 24, and 36 months
Change in social network	Social network will be assessed using the Lubben Social Network Scale-6 (LSNS-6)	Baseline to 12, 24, and 36 months
Cost-effectiveness of the intervention	Cost-effectiveness will be expressed as the incremental cost per quality-adjusted life year (QALY) gained in the intervention group compared with the control group. Costs will include healthcare service utilization and associated costs assessed using CSRI-adapted items and productivity-related information collected using the WPAI. QALYs will be derived from EQ-5D-5L utility scores.	From baseline through 36 months

Collaborators and Investigators

• Sponsor: Yuju Wu

Study record dates

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): September 14, 2026
• Last Update Submitted That Met QC Criteria: September 9, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Neurocognitive Disorders; Cognition Disorders
• Other Study ID Numbers: HXSY-BEC-S2026005

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be publicly available due to ethical and privacy considerations. The collected data contain sensitive health information, and sharing individual-level data may pose risks to participant confidentiality. Data will be securely stored and accessed only by authorized members of the research team for purposes approved by the ethics committee.

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