Electrophysiology of vision after smartphone use

Background Smart phones emit electromagnetic radiation and blue light which cause many effects on retina and CNS. The aim is to investigate MP usage effect on vision in healthy adults by using VEP and ERG and to correlate these effects with age and previous usage duration. Results 70 healthy participants were subjected to one hour exposure to a smart phone set at 30 cm distance from eyes. P-VEP and ERG (pattern, full field flash and multifocal) were recorded pre and post exposure. Correlations with age and with prior history of duration of usage were analyzed. Significant P100 latency delay was reported in P-VEP. No effect on P-ERG was observed. F-ERG showed a high statistically significant reduction in b wave amplitude. MF ERG showed a statistically significant P1 amplitude reduction and latency delay. P100 latency increase showed a positive correlation with age and a negative one with prior exposure duration. F-ERG showed significant negative change in (a) wave latency with age but no significant one with MP usage duration. Regarding MF ERG, there was significant negative correlation of P1 wave with age and with the duration of MP usage. Conclusion Practicing mindful mobile device utilization to minimize possible undesirable effects on vision is advised. These effects were more obvious in central retina. Long duration of previous use of MP increases tolerance of electro-diagnostic tests of vision to acute exposure though impairing basal function. ERG is more affected in young age, but VEP is more impaired in old age after acute MP exposure.