Abstract
Purpose: :
Driver is legally required to pass a vision test before a driving permit is issued. This study compared the casualty accident rates of different cities/countries and also reported the current vision status of Hong Kong commercial vehicle drivers.
Methods: :
Current casualty accident rates and vision–related requirement for driver’s license were collected from the transport departments of 15 Asia–pacific and western cities/countries. Locally, 420 commercial vehicle operators (mean age: 52.74 years old) completed a set of questionnaires on vision and driving–related environmental issues, of which, 361 drivers also participated in a vision screening program. Their habitual distance and near visual acuities, color vision, stereopsis and horizontal temporal visual field were evaluated.
Results: :
Hong Kong has a high casualty accident rate. Exclusion of visual field assessment for drivers in certain cities/countries was significantly associated with higher casualty accident rates (p<0.05). The most prevalent symptoms of the commercial drivers were ocular tiredness (51.4%), itching eyes (44.5%) and tearing (28.3%). Around 80% and 60% of drivers reported sunlight and forthcoming headlight as glare sources, respectively. There were 5% and 65% of subjects had distance and near visual acuities worse than 6/18+2, respectively. Around 18.5% had poor stereoacuity and 9.9% had colour vision deficits. Moreover, 1.9% had temporal visual field less than 70º in any one eye.
Conclusions: :
There is no standardized vision standard adopted by local licensing authorities worldwide. Our findings show that inclusion of visual field test is associated with a lower casualty accident rate. Anterior eye symptoms and glare were common among the commercial vehicle drivers. Ways to improve the visual efficiency of drivers will be discussed.
Keywords: visual acuity • visual fields • binocular vision/stereopsis