title: Driving with central field loss III: vehicle control.
abstract: BACKGROUND
  Visual impairment associated with central field loss may make vehicle control more difficult due to the degraded view of the road. We evaluated how central field loss affects vehicle control in a driving simulator.
  
  
  METHODS
  Nineteen participants with binocular central field loss (acuity 6/9 to 6/60) and 15 controls with normal vision drove 10 scenarios, each about eight to 12 minutes. Speed, lane offset and steering wheel reversal rate were measured on straights, left and right curves, along city (approximately 50 km/h) and rural highway (approximately 100 km/h) routes. Following distance was measured on two city straight segments.
  
  
  RESULTS
  Subjects with central field loss had higher steering wheel reversal rates (0.55 versus 0.45 reversals per second, p = 0.015), suggesting that the steering task was more demanding for them, requiring more steering corrections; however, they did not differ in other performance measures. Nearly all maintained a safe following distance, although they were more likely than controls with normal vision to lose sight of the lead car in scenarios that required following a car.
  
  
  CONCLUSIONS
  Most measures of vehicle control did not significantly differ between participants with central field loss and those with normal vision; however, the higher steering wheel reversal rates suggest that, in compensating for their vision impairment, drivers with central field loss had to allocate extra steering effort to maintain their lane position, which in turn could reduce attentional resources for other driving tasks.
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: P Matthew
authors.initials: PM
authors.lastname: Bronstad
authors.affiliation: Department of Psychology, Villanova University, Villanova, Pennsylvania, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Albu
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Goldstein
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Eli
authors.initials: E
authors.lastname: Peli
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Alex R
authors.initials: AR
authors.lastname: Bowers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001334:Automobile Driving; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012607:Scotoma / Q000503:physiopathology; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity; D014794:Visual Fields
keywords: age-related macular degeneration; driver's vision; low vision