**9.2 Limitations**

Since the study was cross-sectional, it could not show cause-effect relationship. Recall bias was also an expected limitation. Categorization of visual impairment was based on presenting, not corrected visual acuity. HbA1c was not measured due to clients' financial issue so that physicians ordered fast plasma glucose instead of HbA1c. The HbA1C test is a reliable blood test that provides information about a person's average levels of blood glucose over the past 3 months. However, the fasting plasma glucose shows only point in time result of the diabetic patients.
