 For the qualitative observation, the investigators recruited two anthropologists as research assistant RA who had completed their undergraduate and masters on anthropology. who were present during the entire camp hours run by three different service providers in three study upazillas and observed the activities from patients counselling to prescribing eye glass as well as marketing aspects. A total of eight camps were observed in each provider arm in three upazillas by two RA. There was one RA per camp who was assigned to observe two cases and note the steps of the screening process for presbyopia by the BRAC providers and some key features of the camp as per the camp protocol for example, counselling and marketing. The qualitative data were collected using a semi structured observation checklist developed following the presbyopia screening protocol and pretested prior to data collection. Observers were given four days training including a one day practical observation exercise in an eye screening camp on the relevant themes to be observed. A total of 24 cases were observed. The investigators blinded the service providers from the direct observation by the research assistants and it was possible because there were quantitative data collectors present in the camp. Blinding was done to understand the unbiased performance by the intervention groups. Content analysis was adopted to analyse the data according to predefined themes. 