This study investigates the validity evidence of metrics used for the assessment of surgical skills for Manual Small Incision Cataract Surgery (MSICS) in a virtual reality simulator. MSICS surgery is a low-cost, low-technology cataract surgery technique, which is widely used in low- and middle-income countries. However, there is a lack of cataract surgeons globally, and efficient and evidence-based training of new surgeons is needed. In order to investigate the validity of simulator metrics, we included three groups of participants: (1) MSICS novices who were ophthalmologists with no cataract surgery experience, (2) MSICS novices who were experienced phacoemulsification cataract surgeons, but with no MSICS experience, and (3) experienced phacoemulsification and MSICS surgeons. The evaluation included 11 steps of the MSICS procedure, and all simulator metrics for those steps were reviewed. Of the 55 initial metrics, 30 showed high positive discriminative ability. A test passing score of 20 out of 30 was established, and one of 15 novices with no MSICS experience (mean score 15.5) and 7 out of 10 experienced MSICS surgeons (mean score 22.7) passed the test. We have developed and established validity evidence for a test for MSICS skills in a virtual reality simulator for future use in proficiency-based training and evidence-based testing of training interventions.