Effect of Smart Phone on Accommodation and Vergence Response in Bright and Dark Illumination with Different Positions

Background: In modern society, globally the use of electronic device for both professional and non-professional activities has been more prevalent.The relatively small screen found in this device may necessitate close working distance and small text size which may increase the demands placed on ocular accommodation and vergence. Aim:To study effect of smart phone on accommodation and vergence before and after using a smart phone in bright and dark illumination with different position. Methodology:It is a prospective study where the subjects were participated from Sankara college of optometry Bangalore.The following test such as Near point of accommodation, amplitude of accommodation, NRA -PRA Accommodative facility, NPC, vergence facility, Negative fusional vergence and positive fusional vergence evaluation were done.Then, the subjects were made to read a novel on a smart phone in bright and dark illumination in erect and supine position 30 minutes again accommodation and vergence test were repeated.Data analysis was done by using paired T-test with the help of SPSS software V23.The accommodation and vergence functions tests were compared for before and after reading novel on a smart phone in bright and dark illumination in erect and supine position about half an hour.Result: A total of 30 subjects were evaluated under the Mean age group of 19.97 ± 1.67 year (range, 18-30years).Out of 30 subjects, 22(73%) were females and 8(27%) were males.There is significant change statistically and clinically in accommodation components such as NPA, AA and NRA, MEM and Vergence components such as NFV before and after reading novel on a smart phone in bright and dark illumination in erect and supine position about 30minutes. Conclusion:In the current study, we found that prolonged reading of novel in the smart phone in bright and dark illumination in erect and supine position which was for a period of half an hour shows statistically significant effect on accommodative components such as NPA, amplitude of accommodation and NRA, MEM and also there was statistically significant effect on vergence components such as NFV.This study concludes that reading novel for half an hour on smart phone in bright and dark illumination in erect and supine position has effect on the accommodation and vergence function.