Introduction: Usage of smartphones have increased rapidly because of its importance in our daily life. This led to an increase in incidence of ocular problems among smartphone users. This research was conducted to determine the effect of smartphone usage on accommodation status. Methods: A cross-sectional study was conducted among young adults aged 19 to 30 years old in Management and Science University, Shah Alam. All subjects were asked to use smartphone for 20 minutes. The symptoms and accommodation status were evaluated before and after the smartphone usage. Results: Total subjects showed the mean age of 23.60 ± 2.77 years, 50% (n = 20) were males and 50% (n = 20) were females. The mean smartphone usage per day was 8.60 ± 2.80) hours. After 20 minutes of smartphone usage, subjects complained of tired eyes (92.50%), dry eyes (90.00%), blurred vision (87.50%), and headache (82.50%). Paired t-test showed significant reduction in amplitude of accommodation, monocularly from 9.9 ± 1.9 D to 8.76 ± 2.50 D (p = 0.00), and binocularly from 12.01 ± 1.95 D to 10.96 ± 2.16 D (p = 0.00); monocular accommodative facility from 13.93 ± 3.13 cpm to 11.10 ± 4.32 cpm (p = 0.00) and binocular accommodative facility from 12.70 ± 3.57 cpm to 9.70 ± 4.21 cpm (p = 0.00); positive relative accommodation from -2.72 ± 0.87 D to -2.13 ± 1.28 D (p = 0.00) and increase in lag of accommodation from 0.4 ± 0.26 D to 0.93 ± 0.48 D (p = 0.00). Conclusion: This study shows that there were significance changes on accommodation status after 20 minutes of smartphone usage which can lead to weakness of accommodation.