On-road studies have proposed that drivers with eye disease and associated visual impairment aren’t as good at hazard perception; however, open-road assessments can vary due to differences in traffic conditions from one assessment to another as well as the number and nature of potential hazards. A recent study used computer-based hazard perception tests related to driving performance and crash risk to determine that drivers age 65 and older with eye diseases such as cataract, AMD and glaucoma have significantly delayed response times. The researchers also noted that motion sensitivity was most strongly associated with response times, even when adjusted for age and other visual measures.

The study included 99 participants with eye disease and 118 age-matched controls. Participants were asked to tap the computer monitor as early as possible to indicate the location of road users who were likely to be involved in traffic conflicts with the camera car. The researchers measured the response time to selected traffic conflicts from the first point the road user involved in the conflict could be identified to the time when the participant responded.

Participants with eye disease exhibited a 0.73-second delay in response times compared with controls (6.61 seconds vs. 5.88 seconds). Participants with glaucoma demonstrated the slowest response times of all participants. The study noted that slower hazard perception test responses have been associated with increased crash risk and poorer driving performance in both younger and older drivers.

Poorer motion sensitivity, visual acuity and better-eye mean defect were most strongly associated with delayed responses. “Detecting small amounts of motion is an important factor underlying the capacity to detect and predict road hazards within the driving environment,” the researchers highlighted. “This finding is important given that motion sensitivity is impaired in a range of eye diseases, including glaucoma and AMD.”

The study concluded that hazard perception tests can provide insight into difficulties regarding road hazard detection of older drivers with eye disease and offer a potential avenue for interventions to improve road safety.