SIGNIFICANCE:After 6 to 8 weeks of mandatory lockdown due to coronavirus disease 2019 in Spain, the encouraged change in daily habits resulted in a significant increase in electronic device use. Computer vision syndrome-related symptoms were reported more often in participants who used electronic device for more time and spent less time outdoors. PURPOSE:The main purpose of this study was to evaluate computer vision syndrome-related eye symptoms due to the use of electronic devices during COVID-19 lockdown decreed in Spain in 2020.METHODS: After 6 to 8 weeks of strict lockdown, a total of 730 participants (18 to 73 years old) filled in a customized questionnaire divided into three sections: (1) general demographics, (2) usage habits of electronic devices during this period, and (3) computer vision syndrome-related ocular and visual symptoms associated with their use and with ergonomic practices. RESULTS:The daily duration of use of electronic devices increased an average of 3.1 ± 2.2 h/d during the lockdown, with computer use increasing the most. The main symptoms reported by the participants were headache (36.7%), dry eye (31.1%), irritation (24.1%), blurred vision (21.2%), and ocular pain (14.9%). There was a significant relationship between computer vision syndrome-related symptoms and age (greater in participants between 18 and 30 years old than in those older than 45 years, P < .001), primary activity (greater in studying from home and remote working, P < .001), and extended periods of electronic device use (greater when used more than 10 h/d, P = .05). Symptoms were also associated with time spent outdoors (greater in participants with <1 h/d, P = .02). CONCLUSIONS:The lockdown due to COVID-19 showed an increase in the electronic device use. Participants who spent more time with electronic devices and less time outdoors reported more computer vision syndrome-related eye symptoms.