Overview
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.
Eligibility
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 \[VA\] \< 6/18 in the better-seeing eye and improving to \> = 6/18 with spectacles) and/or near VI (presenting near vision \< N6 at 40 cm and improving to \> = N6 with spectacles);
- 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);
