Anatomy of an Intervention

Looking “under the hood” of a major policy experiment

The 2012-2013 Seeing is Learning project involved many moving parts and required plenty of work. Let’s take a closer look at a timeline of events:

Canvassing and Contracting

July 2012 – In mid-summer our field coordinators took their first visits to our sample areas and acquired school lists, secured government support for the study, and travelled to each county seat in our sample (18) to locate local refractionists to help us conduct our screening and eye examinations. This required essentially “knocking on the doors” of optical shops, explaining the project, and soliciting their help. In any future upscaling of the project, leveraging local expertise is imperative.

Refractionist Training

July and August – After securing the support of 18 refractionists in our sample area, we had to make sure that they were qualified to work on this project. To do so, ophthalmologists from Zhongshan Ophthalmic Center trained all refractionists prior to the implementation.

Nurse and Enumerator Training

September – To conduct eye screenings and examinations we recruited about 200 enumerators from local universities, including almost 50 nursing staff. We trained all enumerators to conduct our baseline survey, undertake eye screening, and assist refractionists in performing eye examinations.


Screening and Baseline Survey

September – Our teams of enumerators and eye screeners fanned out across the project areas, visiting schools in our sample county by county. Upon arriving at the schools, each team screened every child in the fourth and fifth grades classes. They recorded which children had low vision and copied that information to the refractionists who were following one day behind. The enumerators also carried out the baseline survey to serve as a benchmark for our study.

Eye Examinations

fSeptember – Our teams of refractionists and nurses followed one day behind the teams of screeners and enumerators. Equipped with autorefractors the teams performed comprehensive eye examinations on all students identified by the screeners as potentially having low vision. Refractionists provided prescriptions to the students and students chose their favorite frames.



Eyeglass Manufacturing 


September/October –For each child in need of glasses we prepared a package with their identifying information, prescription, and chosen model of frames. These packages – more than 3000 of them – were sent to an eyeglass factory in Shanghai. Once the glasses were made, the manufacturer sent them back to the field, ready to be dispensed.

Training for the Information Intervention


October – We recruited 30 staff from local universities to help us conduct our information intervention. Staff were instructed on how exactly we deliver the information. This way we could be sure that all school selected to have the intervention received the same information in the same format, even using the same words. This allowed us to better measure the effectiveness of the intervention.

Information Intervention


October – Having been fully trained, our staff visited half of the schools and in each one conducted the information intervention. Information materials included a short film, a presentation, and an informational pamphlet. All materials were tailored for and directed separately to our target audiences: the children, their caregivers, and teachers.






Distribution (Free and Voucher Schools)


October – This was the fun part! Once again we recruited teams to visit all schools selected to receive free glasses and vouchers for free glasses. Together with our local refractionists, the teams fitted the children’s new glasses onto their face and instructed them on their proper handling and care. There is nothing like seeing a child suddenly able to see clearly for the first time. Truly unforgettable!


November – Glasses are only as good as their prescription. In order to determine whether local refractionists and eyeglass manufacturer prepared accurate glasses for each student, we went to the field to randomly check glasses in some schools to determine whether a) the children’s vision was properly measured and b) whether their glasses were made properly.

Evaluation Survey

In May/June 2013, we recruited a new and eager crew of survey enumerators to execute our evaluation survey. Led by “seasoned veterans” from our baseline survey, the 100 member team headed to the field for 8 days to conduct the survey. Comparing data from this and the baseline survey allows us to measure the impact of our interventions.

Dispensing glasses to control group students

Also in June 2013, we sent teams to the field to dispense glasses to those children that, for the purposes of our study, were randomly selected not to receive them during the baseline in October 2012. To be sure, all the children we have found to have refractive error are guaranteed to have received glasses!






Data cleaning and analysis


Of course, a project of this size creates a wealth of data that we have been busy analyzing in order to confidently determine the effects of the project. Analysis was ongoing throughout 2013, and continues today.


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