The Impact of Uncorrected Astigmatism on Night Driving Performance

• The study was conducted To investigate the effect of uncorrected astigmatism on night driving performance on a closed-road circuit. In this study 10 drivers (mean age 24.4 ± 7.0 years), with low to moderate bilateral astigmatism (0.75-1.50 DC), who were regular contact lens (CL) wearers were included.
• Their vision and night driving performance were assessed in a cross-over design with a toric CL and a best-sphere spherical CL.
• Binocular visual function includes various measures like photopic and mesopic visual acuity (VA), contrast sensitivity (CS), mesopic motion sensitivity and glare tests
• Night-time driving assessment was performance driven which involves measures of sign recognition, hazard detection and avoidance, pedestrian recognition distances, lane keeping, speed and overall driving score.
• There was no significant effects of visual correction type on photopic VA with spherical CL. Correction of astigmatism with toric CL significantly improved mesopic VA, photopic and mesopic CS, mesopic motion sensitivity, and reduced glare (p < 0.05).
• When Toric CL used in correction of astigmatism it results in significant improvements in night driving performance, compared to driving with spherical CL (p < 0.05).

CONCLUSION

• Correction of low to moderate levels of astigmatism had significant positive effects on night-time driving performance and related tests of visual performance which is especial importance for drivers with astigmatism to improve night road safety.

 TAKE-HOME MESSAGE

• In this study the authors show how uncorrected bilateral astigmatism can affect drivers' abilities with night time driving performance even at a low to moderate degree which was not given much importance before.
• The findings from this study establishes role of toric soft lenses and suggest that even a low degree of astigmatism should be corrected with toric soft contact lenses.

REFERENCE

Ophthalmic Physiol Opt 2019 Aug 04;[EPub Ahead of Print], AA Black, JM Wood, LH Colorado, MJ Collins