increasing prevalence rates and ORs of the respective ocular symptoms according to duration of daily smartphone use (hours/day) and lifetime exposure to smartphones (lifetime hours). Increasing ORs of ocular symptoms by longer and continuous duration of daily smartphone use were seen in two ocular symptoms; inflammation (excessive/persistent use OR 1.88, 95% CI 1.12–3.16) and lacrimation (excessive/intermittent use OR 1.96, 95% CI 1.22–3.14; excessive/persistent use OR 2.12, 95% CI 1.31–3.46) Increasing ORs were also seen according to increasing lifetime exposure to smartphones; redness (OR 2.05, 95% CI 1.24–3.38) and lacrimation