Evaluation of the visual acuity in people with carsickness

Abstract

Land transport is a common mode of transportation in Thailand. The severe symptoms of carsickness affect individual’s ability to work and travel, including the daily living. Currently, the exact etiology of carsickness is still unknown but the most accepted assumption is the conflict between visual and vestibular information. These 2 systems work together through the vestibulo-ocular reflex (VOR) to preserve the clarity of image during head motion. Several studies have addressed the function of the VOR in people with seasickness susceptibility, not in people with carsickness. This study compared the visual acuity during head turning to sides in 20 healthy Thai males or females with carsickness susceptibility with 20 age- and gender-matched non-susceptible people. The results revealed that the VA of the susceptible and non-susceptible groups were not significantly different (p>0.05). In conclusion, the visual acuity of people with carsickness susceptibility did not degrade during head motion, reflecting the normal function of horizontal semicircular canal.