Results using the OSCS based on the factor analysis of the seven symptoms also showed a similar tendency in association with daily and cumulative lifetime exposure levels of smartphones (Supplemental Table 1 –online only).Table 3 shows the multinomial analysis by number of ocular symptoms (OSS). Although excessive/ intermittent and excessive/persistent use groups had increased likelihoods of being in the 5–7 OSS group compared to the shorter use group (OR 2.18, 95% CI 1.09–4.39 and OR 2.26, 95% CI 1.11–4.57, respectively), the two ORs were not significantly different in the 95% CIs in both exposure groups. After excluding contact lens users, the excessive/intermittent use group had a 2.21-fold higher likelihood of being in the 5–7 OSS group (95% CI 1.06–4.60), and the excessive/persistent use group had a 2.47-fold higher likelihood of being in the 5–7 OSS group (95% CI 1.16–5.25).