Ocular Surface Disease Index

The OSDI is a 12-item questionnaire that assesses dry eye-induced ocular irritation symptoms and associated visual functions. All participants were asked these questions in face-to-face interviews before and after 1 month of SiHCL use, and their answers were recorded in the system. Each item in the OSDI questionnaire is scored between 0 and 4. As in the original questionnaire, OSDI scores were calculated by summing the points from all 12 items, multiplying by 25, and dividing by the number of items answered to transform the results into a 0-100 scoring system. OSDI scores of 0-12 were regarded as normal, 13-22 as mild, 23-32 as moderate, and 33-100 as severe ocular surface disease.²¹