The questionnaire used in this research (NEI RQL-42) was developed by RAND in the USA, under the sponsorship of the National Eye Institute. The research team are grateful to RAND for freely allowing the reseachers to use the questionnaire.
The questionnaire used in this research (NEI RQL-42) was developed by RAND in the USA, under the sponsorship of the National Eye Institute. The research team are grateful to RAND for freely allowing the reseachers to use the questionnaire.